Chapter 11

DEATH RATE PER 1000 IN PRUSSIA BY AGE GROUPS 1875-80 TO 1901-1910 -----+-----------------+-----------------+-----------------+----------------- | 1875-1880.[T] | 1881-1890.[T] | 1891-1900.[T] | 1901-1910.[U] Ages |-------+---------+-------+---------+-------+---------+-------+--------- | Males | Females | Males | Females | Males | Females | Males | Females -----+-------+---------+-------+---------+-------+---------+-------+--------- 1-2 | 71.8 | 69.1 | 70.2 | 68.0 | 58.0 | 55.5 | 45.3 | 43.1 2-3 | 37.1 | 36.1 | 36.3 | 34.6 | 24.7 | 23.8 | 16.5 | 16.0 3-5 | 22.2 | 21.7 | 20.8 | 20.7 | 14.2 | 13.9 | 8.9 | 8.8 5-10 | 9.3 | 9.2 | 8.8 | 9.0 | 5.9 | 6.1 | 4.2 | 4.4 10-15| 3.9 | 4.3 | 3.8 | 4.3 | 2.9 | 3.3 | 2.4 | 2.7 15-20| 5.1 | 4.6 | 4.8 | 4.5 | 4.3 | 3.8 | 4.0 | 3.6 20-25| 7.7 | 6.3 | 7.0 | 5.8 | 6.0 | 5.1 | 5.2 | 4.6 25-30| 8.6 | 8.2 | 7.6 | 7.5 | 6.1 | 6.1 | 5.3 | 5.5 30-40| 10.9 | 10.3 | 10.6 | 9.7 | 8.3 | 7.9 | 7.0 | 6.7 40-50| 16.7 | 12.3 | 16.3 | 11.7 | 14.3 | 10.0 | 12.5 | 8.6 50-60| 27.6 | 20.7 | 26.9 | 19.8 | 24.2 | 17.5 | 23.5 | 16.0 60-70| 53.0 | 46.3 | 51.4 | 44.8 | 48.7 | 42.0 | 45.5 | 37.4 70-80| 113.3 | 106.2 | 110.2 | 113.9 |102.5 | 97.1 | 100.6 | 102.0 80 & | | | | | | | | over| 236.4 | 227.2 | 238.2 | 229.0 |233.1 | 223.3 | 214.4 | 202.6 -----+-------+---------+-------+---------+-------+---------+-------+---------

Note that in both sexes there was a steady and substantial decline in the death rate at all age periods of life after 1875.

[T] _Koeniglich Statistisches Bureau in Berlin Preussische Statistik_. Hft. 184, p. iv. ff., Berlin.

[U] _Zeitschrift des Koeniglich Preussichen Statistichen Landesamts_, Berlin, 1912, p. xvii.

DEATH RATE PER 1000 IN DENMARK BY AGE GROUPS 1880-1889--1890-1900 --------+-------------------++------------------- | 1880-1889 || 1890-1900 Ages +---------+---------++---------+--------- | Males | Females || Males | Females --------+---------+---------++---------+--------- 0-5 | 53.1 | 46.0 || 48.5 | 40.8 5-10 | 7.2 | 7.7 || 5.6 | 6.0 10-15 | 4.4 | 5.6 || 3.6 | 4.6 15-20 | 4.9 | 5.8 || 4.5 | 4.7 20-25 | 7.0 | 6.1 || 6.0 | 4.9 25-30 | 6.5 | 7.4 || 5.5 | 5.6 30-35 | 6.8 | 7.9 || 6.1 | 6.5 35-40 | 7.8 | 8.4 || 7.7 | 7.5 40-45 | 9.8 | 9.3 || 9.3 | 8.2 45-50 | 12.6 | 10.2 || 11.6 | 9.1 50-55 | 16.8 | 12.2 || 15.7 | 11.8 55-60 | 22.6 | 17.0 || 22.0 | 16.4 60-65 | 33.3 | 26.1 || 30.7 | 24.2 65-70 | 46.9 | 39.2 || 44.7 | 36.7 70-75 | 70.0 | 58.3 || 74.5 | 65.0 75-80 | 104.9 | 92.9 || 115.0 | 98.9 80-85 | 178.7 | 157.4 || 169.4 | 151.6 85-90 | 246.7 | 210.9 || 250.1 | 226.5 90-over| 392.3 | 350.1 || 425.6 | 373.2 --------+---------+---------++---------+---------

Note the improvement in mortality at nearly every age period of life, in both sexes.

_Befolkningsforholdene i. Denmark_ i. 19. Arrhundrede, p. 125. Denmark _Statistiske Tabelvaerk_, Ser. 5, Litra A. no. 5.

DEATH RATE PER 1000 IN SWEDEN BY AGE GROUPS[V] 1801-10 to 1891-00 -------+------+------+-------+------+------+-------+-------+-------+------- Ages | 0-5 | 5-10 | 10-15 |15-25 |25-35 | 35-45 | 45-55 | 55-65 |65 over -------+------+------+-------+------+------+-------+-------+-------+------- Years | | | | | | | | | 1801-10| 79.0 | 12.1 | 7.2 | 8.5 | 11.0 | 14.9 | 22.7 | 40.8 | 111.4 1811-20| 76.0 | 9.7 | 5.6 | 7.2 | 9.9 | 14.3 | 21.0 | 37.6 | 102.9 1821-30| 63.1 | 7.6 | 4.5 | 6.1 | 9.4 | 13.6 | 20.1 | 35.4 | 96.9 1831-40| 60.3 | 7.5 | 4.7 | 6.0 | 9.8 | 14.3 | 20.8 | 35.6 | 102.1 1841-50| 56.8 | 7.8 | 4.4 | 5.5 | 8.0 | 12.2 | 18.1 | 31.8 | 97.1 1851-60| 60.5 | 10.9 | 5.5 | 6.1 | 8.4 | 11.9 | 17.9 | 32.1 | 91.6 1861-70| 57.3 | 9.1 | 4.4 | 5.4 | 7.2 | 10.1 | 15.1 | 28.7 | 87.2 1871-80| 52.3 | 8.5 | 4.2 | 5.3 | 7.4 | 9.3 | 13.1 | 23.6 | 79.4 1881-90| 43.6 | 7.7 | 4.0 | 5.2 | 6.6 | 8.2 | 11.5 | 21.1 | 71.4 1891-00| 36.9 | 6.0 | 3.6 | 5.4 | 6.5 | 7.8 | 10.9 | 19.7 | 71.3 -------+------+------+-------+------+------+-------+-------+-------+-------

Note the pronounced fall in the death rate at every age period during the past century.

[V] _F. Prinzing Medizinische Statistik_, Verlag von Gustav Fischer in Jena, 1906.

[Sidenote: The Remedies]

The remedies, however, are plainly indicated:

1. Eugenics, to improve the stock.

2. Periodic physical examinations to detect the earliest signs of disease, and especially infective foci in the head, such as diseased gums, tooth sockets, tonsils, nasal cavities, etc.

3. The practice of personal hygiene along the lines of ascertained individual needs.

Cancer, another disease heavily on the increase in all civilized countries, may be combated by similar measures.

SECTION IX

EUGENICS

"How to Live" deals mainly with personal hygiene, that is, the proper care of the individual. Hygienic improvement is limited, however, to the attainment of the best of which an individual is capable. Eugenics deals with the even more vital subject of improving the inherent type and capacities of the individuals of the future. It has been but briefly touched upon in this volume.

Eugenic improvement is attainable through the control of heredity. By heredity is meant the action of elements which control the development of the individual, and determine his constitution or makeup. The laws of Nature governing this action are now known in part, so that advantage can be taken of them to bring about the hereditary improvement of the race, generation by generation.

[Sidenote: What Eugenics is Not]

Eugenics is not simply sex hygiene, as many have come to consider it, owing to the liberal use of the word Eugenics by the sex hygienists. Sex hygiene is, of course, one of the considerations in eugenic improvement.

Eugenics is not, furthermore, the science of improving the physical organism only, as has been erroneously assumed by certain uninformed publicists, a point of view which has been promoted by cartoonists, who find it good sport for their pens.

Eugenics does not require the old Spartan practise of infanticide, nor does Eugenics propose to do violence in any other way to humanitarian or religious feeling.

Eugenics does not mean, as some have imagined, compulsory or government-made marriages.

Nor is Eugenics the science of improving the human stock by matings that are academically ideal, but which lack the element of individual attraction and instinctive love.

[Sidenote: Discovery of Hereditary Laws]

There was a time when the inherent personality of a man, the color of his eyes, the capacity of his mind, the quality of his character, seemed clearly subject to the caprice of forces beyond the reach of mortal perception. In attempting to trace the source of a personality, hereditarily, no constancy could be detected in its relation to the lives from which it arose. A child was never absolutely like brother, sister, mother, father or grandparent.

An epoch-making discovery in 1865 by an Austrian monk named Mendel,[57] and later discoveries by a number of other scientists, revealed the subdivisibility of each individual into many distinct units or traits, the hereditary sources of which were clearly traceable, leading to various individuals of the family line, and not to one individual alone. Furthermore, it was found that the lack of a certain trait sometimes appears as a trait in itself, just as darkness seems like a condition in itself rather than as an absence of light.

These discoveries changed the whole current of thought regarding heredity, and the constancy of its action, as well as its controllability. It also emphasized the fact that it does make a difference whom one marries as to the character of the resulting offspring. Their makeup is not subject to the caprice of forces beyond human perception, but is in some degree subject to control.

Out of these discoveries has arisen the science of Eugenics. Sir Francis Galton, of England, was the first to start a world movement for its application toward conscious betterment of the human stock.

[Sidenote: Rules of Eugenics]

From the known laws governing the inheritability of unit-traits, it is apparently necessary, in the betterment of the race, to follow a few important rules:

1. Learn to analyze individuals into their inheritable traits--physical, mental and moral.

2. Differentiate between socially noble and ignoble traits, between social and educational veneer and sterling inherent capacity.

3. Do not expect physical, mental and moral perfection in any one individual, but look for a majority of sterling traits.

4. Observe the presence or absence of specific traits in individuals at all ages of successive generations and fraternities of a family line.

5. Learn how to estimate the inheritability of such traits in a family line, upon specific mating with another family line.

6. Join your family line to one which is strong in respect to the traits in which yours is weak.

7. But remember also that injuries can be inflicted on offspring by unhygienic living.

[Sidenote: Inheritable Traits]

Some of the characteristics in Man's complex known to act hereditarily and to be traceable to distinct sources on family lines are as follows:[58]

_Physical Traits._--Character of the facial features, color of the eyes, hair and skin, stature, weight, energy, strength, endurance, quickness, commanding presence, vivacity of manner, general bodily soundness; also defects of many kinds, such as those of the nervous system, of the speech, eyes, ears, skin, also baldness, defects of the muscular system, blood, thyroid glands, vascular system, respiratory system, digestive system, reproductive organs; also defects and peculiarities of the skeleton, etc. This does not mean that all shortcomings are inherited. It does mean, however, that the type of organism is inheritable which lacks resistance to the germs and other precipitating factors in bringing about the disease.

_Mental Traits._--Among the mental characteristics known to arise from traceable hereditary sources may be mentioned factors in musical ability, artistic composition, literary ability, mechanical skill, calculating ability, inventive ability, memory, ability to spell, fluency in conversation, aptness in languages, military talent, acquisitiveness, attention, story-telling, poetic ability; and, on the other hand, insanity, feeble-mindedness of many types, epilepsy. These are suggestive of the inheritability of many other mental traits not yet studied.

_Moral Traits._--Among the moral traits known to possess inheritable elements are generosity, piousness, independence, industry, will-power, faithfulness, fairness, sociability, reliability, self-reliance, tendency to work hard, perseverance, carefulness, impulsiveness, temperance, high-spiritedness, joviality, benignity, quietness, cheerfulness, hospitality, sympathy, humorousness, love of fun, neighborliness, love of frontier life, love of travel and of adventure. The same may be said of immoral traits, such as criminality, pauperism, delinquency, irascibility, lying, truancy, superstition, clannishness, secretiveness, despondency, slyness, exclusiveness, vanity, cunning, cruelty, quickness to anger, revengefulness, etc.

[Sidenote: Distribution of Traits]

These physical, mental and moral peculiarities are not scattered evenly through the population, but exist on certain family lines only.

For instance, one-tenth of the deaths that occur in the United States are from tuberculosis. But this does not mean that one-tenth of all families die of the disease. On the contrary, some families lose more than half their numbers from it, while other families lose almost none at all. The 10 per cent. is simply the average of all. The percentage is high among the Irish, and low among the Jews. Life insurance companies take consideration of this fact in examining applicants for insurance. A family history of tuberculosis counts against even a healthy applicant, not because of a belief that tuberculosis is directly inheritable, but because non-resistant types, especially light-weights, are known to be transmitted. A profound influence toward checking this malady would evidently be exerted if the matings on the family lines exhibiting the characteristic of susceptibility were to cease, and thus the perpetuation of susceptible types checked.

The same is true of crime. The 80,000 prisoners constantly supported in the United States are recruited not evenly from the general population, but mainly from certain family breeds.[59] Criminality among "The Jukes" is a rule, among Jonathan Edwards' descendants, the exception. The same is true of mental abilities of different kinds. Galton showed that the prominent English judges, statesmen, chancellors, etc., were furnished by certain family lines only, and were not drawn evenly from all families.[60] The same is true of feeble-mindedness.[61]

[Sidenote: Socially Noble and Ignoble Traits]

The question of what traits are desirable and what traits are undesirable might seem, on first thought, rather a difficult matter to determine. Few of us would like to have our neighbor's taste in the matter constituted as a standard of judgment upon our own traits. There is one standard of judgment, however, that is so broad and impersonal and so founded on the elements in society to which all individuals are subject, that it can justly serve as a line of division between the desirability and undesirability, broadly speaking, of individual traits for perpetuation. This is the measurement by the standard of social worth and service commonly designated as "fitness."[62] Above this dividing line may be roughly grouped the genius, the specially skilled, the mediocre, who are a service to society, or at least not a burden. Below this line may be grouped those feeble-minded, paupers, criminals, insane, weak and sick, who are a burden, economically and socially. That is, a person's traits are desirable of perpetuation if so balanced as to render the individual not a burden to others.

It must undoubtedly be true that many families possess, inherently, traits of ability which have never had an opportunity to exhibit themselves. This may account for the apparently sudden appearance of great men and women without obvious hereditary background. It is plainly possible, furthermore, to bring about a special combination of two family lines, the mental traits on neither of which exhibit remarkableness, but which, when combined, bring an extremely happy result.

Mental ability does not depend upon education. Education can only enable an individual to utilize more fully his inherent ability; it cannot increase capacity.

The same is true, of course, of physical capacity. Sandow has an extraordinary muscular ability, developed by certain exercises. Similar exercises will not, however, develop all men into Sandows, no matter how constant their faith and persistent their efforts. Sandow was, we may assume, hereditarily gifted with a superior muscular capacity, which his exercises have enabled him to fully develop. It is true, however, that few people ever realize their full physical and mental capacities, owing to lack of opportunity, inclination, etc., and that there generally exist untold possibilities for improvement for those who wish to get the most out of themselves.

[Sidenote: A Majority of Sterling Traits]

It is apparent that the make-up of an individual is the result of a very complex combination of traits. For this reason, the makeup is not likely to fall heir to all "bad" traits, any more than it is to all "good" traits. Even the feeble-minded, who have fallen heir to such an intensely undesirable trait--or rather, to the lack of intensely desirable traits--in many instances have simultaneously inherited many desirable traits, such as kindness, gentleness and generosity, often lacking in those possessed of scholarly capacities. Many women of the border-line type of feeble-mindedness, where mental incapacity often passes for innocence, possess the qualities of charm felt in children, and are consequently quickly selected in marriage. If a mentally able man possess as an ideal of womanhood other traits than mental capacity, no amount of schooling for his child can make up for the difference between the mental capacity of the offspring of such a mating, and the offspring of a mating with an able-minded woman. Although the trait of able-mindedness is dominant, so that the mating of an able and a feeble mind will result in fairly able-minded offspring, who may even be above the average, mentally, such offspring carry in their own germ plasm the defect derived from their feeble-minded parent, which defect may then be passed on to future generations through the germ plasm from which their children get their inheritance. A mother's hereditary influence on the child is just as important a factor as the father's, generally speaking. Where feeble-mindedness exists on a family line, care should be exercised by the able-minded members of that line not to mate with another line possessing cases of feeble-mindedness, lest the offspring then fall heir to feeble-mindedness, which can skip a generation. An appreciation of what is feeble-minded, and a realization of its inheritability can not help but modify a man or a woman's admiration for the traits or lack of traits which it embraces.

Persons possessing weak physical makeups may possess strong mental capacities, and vice-versa. Persons of superior mental capacities may lack loftiness of character. It might happen that in so mating as to prevent the perpetuation of an undesirable trait, physical, mental or moral, a desirable trait would be lost along with it. In any mating transaction, therefore, choice must necessarily compromise upon the favorable hereditary action of a majority of the traits on the two family lines. One must relinquish any quest for perfection. After eliminating the individuals possessing the grossly unsocial traits below the dividing line of social fitness, one must choose with respect to a majority of socially fit traits, in addition to the elements of personal congeniality and affinity. The two last-named elements, however, generally serve as useful narcotics in blinding the mating individuals to the existence of the compromise, and the real becomes the ideal.

[Sidenote: Successive Generations and Fraternities]

Each trait in the mosaic of one person is transmitted or not transmitted to a child according to the mating of that particular trait--mating with trait or lack of trait--rather than according to the mating of the two persons as a whole. That is, when a man and woman marry and bear offspring, it is not the mating of two units, but it is the mating of myriads of pairs of units--the units being the constituent traits and lack of traits (contained in some mysterious way in the germ plasm), each trait-mating producing its own trait-offspring. The collection of these trait-offspring makes up the child.

It has been observed that traits differ with respect to their action in mating. Given a specific type of trait-mating, say of a trait with like trait, or trait with the lack of that trait, some types always reappear in the next generation or else are lost entirely from the family line unless reinfused, whereas other types of traits may not reappear in the next generation, but still appear in a generation further removed. Another type of trait is transmissible only by one sex of a family line, and can not be transmitted by the other sex.

From these facts, it is readily understandable how important becomes the consideration of the marriage of relatives, such as cousins,[63] who are, of course, individuals of the same family line, whose mating brings together like groups of traits, thus strengthening the existence of these traits, whether desirable or undesirable. Cousin marriages, when the family possess traits of mental ability, may result in children who are geniuses; but cousin marriages, when the family line possesses traits of mental inability, may result disastrously with respect to offspring. Family lines possessing traits of mental weakness should most assuredly join only to family lines possessing traits of strength in those regards.

In calculating the inheritability of traits, it is also necessary to consider that certain physical, mental and moral traits flower at the arrival of certain ages only. It is necessary to look along the whole line of a life, as traits may exist at one age and not at another. A boy's beard does not appear until puberty. Likewise, other physical and mental and moral traits sometimes do not manifest themselves until specific ages, according to the type of the family breed. Because a parent dies before the development of the trait does not preclude its transmissibility to his offspring. Huntington's chorea, an extremely undesirable trait, does not develop until middle life, but is transmissible to offspring even though the father dies from some other cause before the period when the disease in his own person would be expected to appear.

[Sidenote: Results of Specific Matings]

[Sidenote: Andalusian Fowl]

We can best understand the laws governing the inheritance of traits by taking a few concrete cases. The first case is that of an Andalusian fowl. We shall consider the two species, pure bred black and pure bred white, and confine ourselves to observing the inheritance of the single characteristic, plumage _color_. Of course, as long as the black mate only with the black their children will be black, and as long as the white mate with white the children will be white. But if a white mates with a black, the children will not be either black or white, but blue. All will be blue. But the most interesting facts appear in the next generation, when these hybrid blue fowls mate with black or white, or with each other. The original of the cross between the white and the black is an entirely new color blue, which may be considered a sort of amalgam of black and white. But a cross between the blue and the black will not be any new color, but will be either black or blue--and the chances are even. That is, in the long run about half of the children of the blue and black parents will be blue and half will be black. None of the children will be white. So also crossing the blue with the white will result in half of the children being blue and half, white. Still more curious is the result of mating blue with blue. One might imagine that in this case all the children would be blue, but only half will be blue, while a quarter will be black and a quarter white.

[Sidenote: Laws of Chance]

These laws are a curious mixture of chance and certainty. In certain circumstances, as we have seen, we can predict with certainty that the offspring will be black, white, blue, or whatever the case may be. In other circumstances we can only state what the _chances_ are. But these chances can be definitely stated as one in two, one in four or whatever it may be, and where there are large numbers of offspring this amounts to a practical certainty that definite proportions will have this or that color, or other characteristics.

Two parents are like two baskets or bundles of traits from which the child takes its traits at random. In the wonderful play of Maeterlinck's, called the "Bluebird," we are taken to the "land before birth," where the children are waiting to be born, having selected their parents to be. Of course, this is only a pleasant fancy, like the advice of Oliver Wendell Holmes to children to choose good grandparents, but it is a useful fancy which will help us to understand the laws of heredity. The child of the Andalusian fowl takes its color from its two parents on the same principle as a lottery in which it would take two beans, white or black as the case might be, from each of two baskets. Every individual is a sort of basket containing two beans, as it were. It took one of these two beans from each parent and will give one to each child.

With this picture of a bean lottery before us it is very easy to understand how the colors of Andalusian fowls are inherited. When two black fowls mate, the offspring must be black, because in this case each parent basket contains a pair of black beans, so to speak, so that the child taking one black bean from each basket will necessarily have a black pair. For the same reason the child of two white fowls must be white, but when a black and white fowl mate, the child takes a white bean from one parent and a black from the other, its own color being resultant or amalgam of the two, which in the case of the Andalusian fowl is blue. Since every such hybrid child has this same combination of a white and a black bean, all these hybrids are alike. All are blue. It is important to remember that this hybrid blue is only a sort of mechanical mixture of black and white, and that the black and white are still separate beans, as it were.

But now suppose a hybrid or blue fowl to mate with a white. This means that the child takes from the white parent or basket one of the two white beans and from the blue parent or basket, one of the two beans, of which one is white and the other, black; the bean taken from the first or white basket must be white, but that taken from the second or blue or hybrid basket may be either white or black. It is a lottery with an even chance of drawing white or black. In the long run, half of the children will draw white and half, black. Those which draw the white will, since they also drew white from the other parent, be wholly white, but those which drew the black will be blue, since they will have one black and one white bean. We see, too, that the white child is just as truly white as though it had not had a hybrid parent; for of the two elements or beans which the hybrid carried, the black one was left behind untaken. We see that the blue child is a hybrid exactly like its hybrid parent, and not any new kind of cross between the blue and the white. In short, the children of a blue and white are either the one or the other and not a mixture. In the same way if a blue mates with a black, half of the children will be black and half blue.

Finally we come to the mating of a blue with a blue. Here the lottery is to pick a bean from two baskets, each basket containing both white and black beans in equal numbers. When at random one is taken from either of these two baskets there is an even chance that the bean from the father is white or black and an even chance that the bean from the mother is white or black.

Now, what is the chance that the child draws a white bean from both baskets? Evidently it is one chance in four; for there are four ways equally probable in which you can take these beans, viz.: (1) black from the father basket and black from the mother, (2) white from the father and white from the mother, (3) white from the father and black from the mother, (4) black from the father and white from the mother. So the children could draw both white once in four times, both black once in four, and a white and a black in the other two cases. And that is why from two blue Andalusian fowls, on the average you will have one-quarter of the children black, one-quarter white, and the other two-quarters, blue. Again let us stop to emphasize the fact that the black children of these hybrids are just as pure blooded as their black grandparent, and will mate with other pure-blooded black in exactly the same way as though there had never been any white in their ancestry. The white strain has been left behind, or been "bred out."

We have spoken of one character or characteristic--color. The same laws apply to other characters. Often different characters are inherited quite independently of one another. Each of us is a basket or bundle of very many qualities, each quality being a little compartment of the basket with two beans in it. There is, as it were, a pair of beans for every unit trait, whether that trait relates to color, to musical ability, or to any one of hundreds of other kinds.

To summarize the laws of inheritance of the unit character called color, in Andalusian fowl, we have really six ways in which we can consider mating of the three colored fowls (black, white, blue): (1) black may mate with black, in which case all the offspring will be black, (2) white may mate with white, in which case all the offspring will be white, (3) a black may mate with a white, in which case the offspring will all be blue--a hybrid containing both black and blue elements, (4) blue may mate with a black, in which case half the offspring will be pure bred black, and half hybrid blue, (5) a blue may mate with a white, in which case half the offspring will be white and half blue, (6) blue may mate with blue in which case a quarter of the offspring will be white, a quarter black and a half blue.

[Sidenote: Guinea Pigs]

These results are the fundamental laws discovered by Mendel. But the results are not always as clear as in the case of the Andalusian fowl. In that case the hybrids were not like either parent, but were a new color, blue, so that they were labeled at once and recognizable as hybrids--but this is not generally the case. Take, for instance, guinea pigs. What will be the result of mating an "albino" white with a black guinea pig? Quite exactly the same principle applies as in the case of the Andalusian fowl, but the principle is not as clear to see. All the offspring are hybrid, but they will not be blue: they will be black. They will look like the black parent, but they are different. The black color predominates; i.e., black is "dominant" over white, while the white recedes out of sight, or is "recessive." This hybrid black guinea pig is like the hybrid blue Andalusian fowl. It is a hybrid, a combination of white and black, but in the guinea pig the black covers up the white so that _nothing_ in the color reveals the fact that it is a hybrid. Now if the hybrid black offspring of these black and white guinea pigs mate with each other, the result will follow exactly the same Mendelian law as applied to the Andalusian fowl. But this will not be so clear, because now we have two kinds of black instead of a black and a blue. One child in four will be _pure bred_ black like the grandparent and two out of the four will be _hybrid_ black. So to the eye we shall simply have, out of four children, one white and three black. But those three black are not all alike. One is a thoroughbred and two are half-breeds.

But how then are we to distinguish between the one pure bred black, the thoroughbred, and the two blacks that are hybrids so that we can be sure which is which? The only way they can be distinguished is to wait to see what their offspring will be in the next succeeding generations.

The one that is a thoroughbred will behave like a thoroughbred. For instance, if mated with white they will have nothing but black children. But if one that is hybrid black mate with one that is white, only half of the children will be white; these white children reveal the fact that their black parent was a half breed. Then we can put a tag on that black parent. If proper tags are put on the blacks so as to distinguish between the pure-blooded and the half-blooded--say a blue tag on the hybrids and a black on the thoroughbreds--we shall get exactly the same results as described in the case of the Andalusian fowl, in the six cases mentioned. The same principles apply to qualities of the guinea pigs other than color. Thus, if a long-haired guinea pig mates with a short-haired guinea pig, all the offspring will be short-haired, because short hair is dominant over long hair. Again, if a smooth-coated guinea pig mates with a rough-coated one, the result will be rough coated, because a rough coat is dominant over a smooth coat.

[Sidenote: "Thoroughbred" Humans]

The same principles undoubtedly apply to the human race, although as yet only a few traits have been carefully studied. Eye color is one of these. Imagine a marriage of a thoroughbred, black-eyed Italian with a thoroughbred, blue-eyed Irish. What will be the result? All the children will be black-eyed, black being dominant over blue; but these black eyes are not the genuine article that the Italian parent possessed. They are a blend, and it is only because the black element dominates over or conceals the blue element that we can not see on the surface that there is any blue there. But it may come out in the next generation; for, if these half-blooded individuals marry among themselves one-quarter of their children on the average will be blue-eyed. The other three-quarters will be black-eyed, but only one-quarter will be "really and truly" black-eyed, i.e., black-eyed like the Italian. The remaining half are hybrid black, like the parents. It is only a sort of imitation black so to speak.

The appearance of blue eyes in the second generation is the long observed but formerly mysterious "atavism," or reversion to the grandparent.

Suppose the children of an Italian and an Irish parent intermarry with pure bred Italians. We immediately know what will be the result. All the children will be black-eyed, but among a large number only half will be thoroughbred black-eyed. The other half will be "imitation" black-eyed. The case is just like the mating of hybrid black guinea pigs with thoroughbred black guinea pigs, or of the blue fowl with the black. Similarly, if the Irish-Italian hybrids marry with pure Irish, half the offspring will be blue-eyed and half will be hybrid black-eyed.

[Sidenote: Dominants and Recessives]

Black eyes are "dominant" over blue eyes because the black color is due to a pigment, while the blue color is due to the absence of this pigment. In general a quality which is due to the presence of some positive element is dominant over a quality due to the absence of that element. A child inheriting from a blue-eyed person simply draws a blank from that side in the lottery.

In order to understand how these principles of Mendel apply in any given case we need first to know what traits are "dominant" and what are "recessive."

Among traits known to be "dominant" are, besides pigmentation of the eye, certain peculiarities of the skeleton, such as short-fingeredness (two phalanges only on each digit), Huntington's chorea, presenile cataract, congenital thickening of the skin, early absence of hair, diabetes insipidus, stationary night-blindness, liability to periodic outbreak of temper, etc.

Among traits known to be "recessive" are albinism (or lack of pigmentation), a certain degenerative disease of the eye, deafmutism, imbecility, insanity of certain types, certain nervous diseases; also mental traits, such as musical ability.

Suppose now that a normal or "strong-minded" person, if we may use that term as distinct from feeble-minded, marries a feeble-minded person. Assuming that the "strong-minded" person is a "thoroughbred" all of the children will be apparently normal. None will be feeble-minded. "Strong-mindedness" is dominant over weak-mindedness. Yet all these children that seem to be perfectly normal lack something in their bodies. This deficiency is simply covered up but can crop out in later generations. If two of these hybrids between the weak-minded and the strong-minded marry each other, one-quarter of the children will be feeble-minded, one-quarter thoroughbred strong-minded and the remaining half, though apparently strong-minded, will carry the taint in them just as their parents did. They are half-breeds. On the other hand, if two feeble-minded people marry, all of the children will be feeble-minded. Certainly we can and ought to forbid and prevent such marriages.

But feeble-mindedness is a recessive quality, so that if the feeble-minded marry only with normal individuals, the feeble-mindedness does not blight the next generation, and if these apparently normal children of such marriages take pains to marry only really normal individuals, avoiding not only the feeble-minded but even those like themselves who have feeble-mindedness on one side of their family tree, there will be no feeble-mindedness cropping out in future generations.

[Sidenote: Instances of Eugenic Improvement]

But not all human abnormalities are recessive. Thus Huntington's chorea is dominant, so that every child of the unfortunate victim of this malady will contract it when it reaches the right age. Marriages of such people should, therefore, never be allowed, even with normal individuals.

But when we propose to restrict marriages or mating of those unfit to marry, people are apt to say, "That is a dream. It can't be done." But it can be done and it has been done. Every one has heard of the cretins in Switzerland. They are a kind of idiot who are short in stature and afflicted in all cases with goitre in the neck. Of course, many people have goitre who are not cretins, but there is no cretin who has not goitre. These cretins are peculiarly a feeble-minded people. They are common still in many towns of Switzerland; they are loathsome objects, helpless as children, with silly smiles, unable to take care of themselves in even the simplest toilet ways, and have to be looked after like domestic animals, or even more closely.

A gentleman very much interested in Eugenics visited Aosta, in Italy, just outside of Switzerland, once in 1900 and again in 1910. In 1900 he found many of these creatures among the beggars in the streets, in the asylums, in the home, in the orphan asylum--everywhere he ran across these awful apologies for human beings. But in 1910 he found only one! What had happened? Simply that a few resolute intelligent reformers had changed the entire situation. An isolation institution, or rather two institutions, one for the men and the other for the women, were established. In these the best care of the inmates was taken as long as they lived, and they do not live long. But pains were taken to see that by no possibility could marriage or mating of those people take place. They forfeited any such rights in return for the care that they received from the State.

Thus is it possible to apply the laws of heredity as laid down by Mendel in a thoroughly practical way and to get results _immediately_ in one short generation. It seems, and it is, a colossal task to change average human nature one iota. Yet in the light of modern eugenics we could make a new human race in a hundred years if only people in positions of power and influence would wake up to the paramount importance of what eugenics means. And this could be done quietly and simply without violence to existing ideas of what is right and proper. It could be done by segregation of the sexes for defectives, feeble-minded, idiots, epileptics, insane, etc. By this kind of isolation we can save the blood-stream of our race from a tremendous amount of needless contamination.

And it is being done. The growing tendency to put defectives in institutions, though originally with no such object, will reduce the transmission of defects, especially when it is recognized that the sexes must be separated and that the inmates should be kept at the institution through the reproductive period of life.

[Sidenote: Educational Influence]

It is inconceivable that the average individual will deliberately and consciously make his calculations regarding the character of possible offspring before he allows himself to fall in love to the point of desiring marriage. Yet unconsciously an educational influence on love and on marriage selection has been operating through centuries. The sick, the feeble-minded, the immoral, and members of their families, have at all times been socially handicapped, and have always been the first to be eliminated in marriage selection. And it is conceivable that this already developed wisdom in mate-choosing can easily be augmented by a further knowledge of heredity which is now available. It unconsciously favorably modifies the individual taste.

Certain races of men, without consciousness of their action, have varied in the character of their choices (sex selection) in such a way as to bring about varied conditions in their races, with respect to resistance to disease, of mental capacity and to moral quality. The Mongolian differs from the Hebrew, the Anglo-Saxon differs from the African.

It depends largely upon the action of those now upon the earth, who are now making their choices of marriage, as to whether the races of the future shall be physical, mental or moral weaklings, or whether they shall be physically brave and hardy, mentally broad and profound, and morally sterling.

[Sidenote: Summary]

To summarize: There are three main lines along which eugenic improvement of the race may be attained:

(1) Education of all people on the inheritability of traits; (2) segregation of defectives so that they may not mingle their family traits with those on sound lines; (3) sterilization of certain gross and hopeless defectives, to preclude the propagation of their type.

There would seem to be great need of State Eugenic Boards, to correlate and to promote these activities, in the interests of the future population, and to give expert advice as to how to legislate wisely, and individual advice as to how to mate wisely. The latter function now falls entirely upon the Eugenics Record Office at Cold Spring Harbor, where the work is being carried on with great efficiency with the funds at command.

_REFERENCES_

[57] Darbishire, A. D.: _Breeding and the Mendelian Discovery_, Cassell & Company, Ltd., London, New York, Toronto and Melbourne, 1911.

[58] Davenport, Chas. B.: _Heredity in Relation to Eugenics_, Henry Holt & Company, New York, 1911.

[59] Dugdale, Robert L.: _The Jukes_, G. P. Putnam's Sons, New York and London, 1910.

[60] Galton, Francis: _Hereditary Genius_, D. Appleton & Company, New York, 1870.

[61] Goddard, Henry H.: _The Kallikak Family_, The Macmillan Company, New York, 1912.

[62] Kellicott, William E.: _The Social Direction of Human Evolution_, D. Appleton & Company, New York and London, 1911.

[63] Huth, Alfred Henry: _Marriage of Near Kin_, Longmans, Green & Company, London, 1887.

[64] Darwin, Charles: _The Descent of Man_, Thomas Y. Crowell & Company, New York, 1874.

For further bibliographic lists, see bulletins entitled "Books and Journals," and "Publications" issued by the Eugenics Record Office, Cold Spring Harbor, N. Y.

INDEX

Abdominal muscles, beneficial effects of erect posture on, 57.

Acids, excess of, from overabundance of animal proteins in diet, 39; fruit and vegetable, in a mixed diet, 43.

Activity, necessary to living a hygienic life, 89; work and play the two great forms, of, 89.

Adulterants in foods, harmful, 65.

Advertising, measures of reform in, 162-163.

Agar-agar, a preventive of constipation, 52-53; for use in colds, 279.

Air, the first necessity of life, 7; motion, coolness, humidity, and freshness of, important features of ventilation, 7; the matter of drafts, 8-9, 123-124, 274, 277; securing fresh, through windows, 9-10; prevention of stagnation of, by air-fans, 10; action of different heating systems, 10; importance of coolness of, 10-11; securing proper degrees of dryness and humidity, 11-12; lighting systems and, 13; evils of tobacco smoke and of dust, 13; bacteria in, carried by dust particles, 13-14; benefits of sunlight, 14; wearing of clothing which admits, 14-15, 275; benefits of out-of-door, 18-20, 276; outdoor sleeping, 20-24, 104, 220, 276; deep breathing, 24-27.

Air-baths, taking of, 15-16, 148.

Air-fans, use of, 10.

Alcohol, modern movement against, 3; poisons in, 65, 241; ill effects of, 67-68; resistance to infectious diseases weakened by, 68; social evil traceable to, 123; to be avoided in cases of overweight, 216; statistics of influence of, on longevity, 227-235; per capita consumption of, in various countries, 235-236; laboratory and clinical evidence relating to physiological effects of, 236 ff.; effect on brain and the nervous system, 237-239; influence on bodily resistance to disease, 239-240; effect on heart and circulation, 240-241; food value of, 241-242; effect on offspring, 243; attitude of National Council of Safety toward, 244; condemnation of, shown by restrictive and prohibitive measures of governments, 244; references on subject of, 244-249.

Alkaline dentifrices, 86.

Amusements. See Recreation.

Andalusian fowl, illustration from, of action of hereditary traits, 307-313.

Anglo-Saxon race, effects of indoor living upon, 147.

Animal cells, apparent immortality of, 142-143.

Apoplexy, death rates from, 284, 285.

Appetite, misleading of, by delicacies of civilization, 151-152.

Apples, food value of, 30, 177, 179.

Arch supports for flat foot, 224, 225.

Arteries, tobacco and diseases of the, 69, 263.

Arthritis deformans, caused by focal infection, 82.

Asparagus, food value of, 41, 175.

Asthenic droop, cause of, 58.

Athletes, effects of tobacco on, 68, 69, 257-259.

Athletics, ideals in, 96; injuries from college, 96.

Attention, control of, essential to securing equanimity, 115.

Autointoxication, meaning of, 81; intestinal intoxication distinguished from, 81-82.

Avocation, practise of an, 98.

Bacteria, carried on dust particles, 13-14; part played by, in colds, 272. _See_ Germs.

Balanced ration, classification of foods with view to a, 171, 175-183.

Bananas, food value of, 30, 177; digestibility of, 49; a cheap source of starch and sugar, 131.

Bank employes, unsuspected impairments among, 136-137.

Basal metabolism of the body, ascertaining the, 196-197.

Baseball, value as all-round exercise, 98.

Bathing, importance of, for avoiding disease, 75-76; perspiring before, 76; activity and relaxation combined in, 101-102; as a means of skin training, 274-275.

Baths, different forms of, for different needs, 102; nervous relaxation induced by neutral, 102; for colds, 278-279.

Beans, baked, food value of, 29, 175; a high-protein food, 38; protein in, a possible objection, 39-40; a cheap source of protein, 131.

Bedbugs, diseases spread by, 74.

Beds, hard preferable to soft, 104.

Beets, food value of, 41, 175.

Belts, constriction from, 16.

Benedict, F. G., experiments by, to ascertain basal metabolism, 196-197.

Berries, food value of, 41, 177.

Blindness among tobacco smokers, 264.

Blood pressure, influence of deep breathing on, 25.

Bowels, foods the best regulators of the, 52. _See_ Constipation.

Brain, effect of alcohol on, 237-239.

Brain workers, eating habits of, 34-35.

Bread, food value of, 29, 180; stale and crusty preferable to soft fresh, 41; a cheap source of starch and sugar, 131.

Breathing, deep, 24-25; influence of muscular exercises on, 26; beneficial effect of singing, 26; relation of, to one's mental condition, 26-27.

Bulk, a necessary quality in food, 41-42, 150.

Bush, A. D., tests by, as to smoking and mental efficiency, 260.

Butter, food value of, 30, 33, 181.

Cabbage, cellulose in, 41; food value of, 131, 175.

Cakes, table of food values of, 179.

Calories, fuel-units for measuring food, 28.

Cancer, measures for combating increase of, 292.

Candy, over-indulgence in, 48.

Cantaloupe, food value of, 30, 177.

Carbohydrate, function of, as a constituent of food, 35-36; examples of, in common foods, 36; suitable proportion of, in diet, 40; in cheap foods, 131; list of foods rich, moderate and deficient in, 171.

Card-playing, mental recreation from, in moderation, 100.

Catarrh, sometimes caused by smoking, 264; avoiding quack cures for, 280.

Cathartics, avoidance of, 53.

Cauliflower, food value of, 41, 175.

Celery, cellulose in, 41; vitamins supplied by, 42; food value of, 175.

Cellulose, a necessity in diet, 41.

Cereals, laxative quality of, 52; table of food values of, 180-181; for underweight, 220.

Chairs, effect of, on sitting posture, 60-61; among the evils of civilization, 152.

Character, posture and, 63-64; influence of health on, 105-107.

Charts, showing comparative mortality among abstainers and non-abstainers, 230-233; of death rates in different countries and at different periods, 283-285.

Cheese, food value of, 29, 38, 131, 181.

Cheeses, putrefactive, among the worst foods, 48.

Chewing, necessitated by hard foods, 41; importance of thorough, 44-47. _See_ Mastication.

Children, results of faulty posture in, 62; sleep required by, 103; effects of alcoholic indulgence by parents on, 243.

Choice of foods, effect of slow eating habits on, 47.

Cigaret smoking, special evils of, 261.

Cigars and cigarets, nicotin in, 254-255; physical and mental effects of smoking, 255-267; increase in use of, 267-268.

Circulation, effect of alcohol on, 240-241; effect of tobacco on, 256, 259-260, 263, 267.

Circulatory system, death rates from diseases of the, 284, 285.

Civilization, hygiene and, 143-156.

Cleanliness, importance of, for avoiding infections, 75-76.

Clerks, unsuspected impairments among, 136-137.

Clothing, relation of, to ventilation, 14; hygiene of, 14; desirability of porous, 14-15, 275; evils of tight, 16; choice of cotton, linen, and woolen, 17; color of, 17-18; artificial conditions as to, resulting from civilization, 147-148.

Cocktail drinking, a harmful habit, 67.

Colds, popular exaggeration of danger of, from drafts, 8, 123; usual origin of, in germs, 8-9, 70-71; measures for avoiding, 9; sometimes indirectly caused by constipation, 51; popular delusions concerning, 123-124; means of infection, 272; sometimes due to abnormalities in nose or throat, 272-273; prevention of, by attention to rules of individual hygiene, 273; chief preventive measures, 273-277; emergency treatment of, 277-280; possibility of avoiding, altogether, 280.

Color of clothes, 17-18.

Concentrated foods, objection to, 41, 150.

Condiments, hot, to be used sparingly, 48.

Constipation, evils of, 51-52; effects of water-drinking habits on, 52; foods which prevent, 52; use of mineral oils for, 53; avoidance of drugs, 53; an enema a temporary expedient, 53; value of massage of the abdomen, 53-54; favored by high-seated water closets, 54; importance of establishing proper habits, 55; poisoning from decomposition of protein in the colon, and remedies, 56; produced by a slouching posture, 57; mental effects of, 106-107; effects of, ascribed to overwork, 124; predisposition to colds caused by, 276.

Consumptive stoop, ill effects of, 57.

Cooking, loss caused in certain foods by, 42; necessary for some foods, 43.

Corn, food value of, 29, 175; cellulose in, 41.

Cornaro, "The Temperate Life" by, 142.

Corsets, constriction from, 16.

Cost, of food, 129-131, 184-190; wholesale, of uncooked ingredients of standard foods, 192-193.

Cotton, use of, in clothing, 17.

Cottonseed oil, a cheap source of fat, 131.

Country life, advantages of, 18.

Cousins, marriage of, 305-306.

Crawling exercise for faulty posture, 222-223.

Cream, food value of, 30, 33, 181.

Crime, laws of heredity applied to, 299-300.

Cucumbers, cellulose in, 41; food value of, 175.

Daily rhythm, observance of a, 89-90.

Dairy products, table of food values of, 181.

Dampness of air, exaggeration of evils of, 19.

Dancing, question of hygienic value of, 99-100; an obstacle to efficiency when overdone, 100.

Death rate, lowering of, by public hygiene, 158-159; statistics of overweight, 213; influence of alcohol on, 228-235, 262; influence of tobacco on, 262; fall of, in younger age groups, and rise at older age periods, in United States, 281; cause of increase in, 282; charts showing trend of, 283-285; comparison of, among different nations, 286-291.

Defectives, segregation and sterilization of, 321-322, 323.

Degenerative tendencies among nations, comparison of, 286-292.

Delusions, certain popular, concerning diseases, 123-125.

Denmark, mortality statistics of, 291.

Dental clinic, beneficial results of, 88.

Dental decay, process of, 79.

Dental floss, use of, 85.

Desires, controlling intensity of one's, 117-118.

Desk, posture in sitting at a, 61.

Despondency, sometimes caused by a slouching posture, 57.

Desserts, table of food values of, 179.

Diabetes, in relation to focal infection, 82; aggravations of, 123.

Discontent, physical sources of, 105-106.

Diseases, caused by absence of vitamins from food, 42; carried by mosquitoes and flies, 71; caused by focal infection, 82; preventability of, 135-136; relation between consumption of alcohol and increase in degenerative, 235-236; effect of alcohol on bodily resistance to, 239-240; caused by smoking, 263-264; signs of increase of the degenerative, 281-285.

Disinfection of foods, 43.

Drafts, unreasonable prejudice against, 8; exaggeration of idea that colds are derived from, 8-9; popular delusions concerning, 123-124; exposure to, a means of skin training, 274; avoidance of, after catching cold, 277.

Drugs, avoidance of, for constipation, 53; habit-forming, as poisons, 65; alcohol to be classed among, 242.

Dryness of air, 11, 19; question of ill effects from extreme, 12.

Duodenum, ulcer of, caused by focal infection, 82.

Dust, air vitiation from, 13; methods of removing, 13; bacteria carried by, 13-14.

Dusty trades, morbidity and mortality rates in, 13.

Dyspepsia among smokers, 264.

Eating, before retiring, 103; in case of colds, 279-280.

Eating habits. _See_ Food.

Education on inheritability of traits, need of, 323.

Eggs, food value of, 29, 38, 183; for underweight, 220.

Emetin, use of, in treating pyorrhea, 85-86.

Emotions, exercise of the, 97.

Endurance, experiments to determine effect of different diets on, 197-199; experiments with mastication, and instinctive eating, 200-209.

Enema, use of, for constipation, 53.

England and Wales, trend of death rate in, 283-284; mortality statistics of, 287; expectation of life in, 290.

Enjoyment of food, desirability of, 46-47, 201-202.

Enthusiasm in exercise, 95-96.

Equanimity, secret of, 115.

Ether, habit of using, as a stimulant, 242.

Eugenics, importance of, 157; distinction between other branches of hygiene and, 157; aim of, 163-165; implies right care of racial germ-plasm, 165; and wisdom of choice in marriage, 165-166; ability of science of, to guide race to higher levels, 166-167; knowledge of, both a personal advantage and a social necessity, 167; main features of thoroughgoing program of, 167; importance for future generations, 167; grandest service of science to the human race, 167-168; a remedy for degenerative tendencies, 292; scope of, 293; correction of popular misconceptions, 293-294; discovery of hereditary laws, resulting in science of, 294-295; rules of, 296; instances of improvement from application of principles, 319-322; three main lines of eugenic improvement, 323; need of State Eugenic Boards, 323-324; references on, 324.

Exercise, times for taking, and benefits, 16; necessity for, to offset evils of a sedentary life, 94; different forms of, 94; after eating, 94; outdoor, in winter, 95; question of enthusiasm in, 95-96; ideals in, 96; of mind, will and emotions, 97-98; dancing as, 99-100; for overweight, 217; for underweight, 220.

Exercises, breathing, 25-26; breathing, for correcting evils of bad posture, 58; corrective, for faulty posture, 62, 221-223; for flat foot, 223.

Expectations of life, comparison of, in different localities, 290.

Eye-strain, evils resulting from, 93; preventive measures, 93-94; remote effects of, 122.

Fads, avoidance of, in matter of diet, 50.

Fans for keeping air in motion, 10.

Fat, function of, as a constituent of food, 35-36; examples of, in common foods, 36; suitable proportion of, in diet, 40; as laxative food, 52; in cheap foods, 131; list of foods poor and rich in, 171; fat-forming food to avoid in cases of overweight, 216; forms of, for underweight, 220.

Fatigue, cautions regarding eating in a state of, 35; relation of posture to, 57; connection between colds and, 70, 276; relaxation a remedy for, 101; value of baths, for, 102; avoidance of, in cases of underweight, 220.

Feet, misdirected, 59-60; correct position of, in standing and walking, 60; exercises for the, 223; disturbances of health due to weak, 224; means of detecting weak, 224-225.

Figs, laxative quality of, 52; food value of, 179.

Fires, ventilation by wood or grate, 10.

Fish, a high-protein food, 38; special objections to an abundance of, 39.

Fisher, George J., smoking tests conducted by, 259-260.

Flat foot, cause of, 59-60; toeing-in and exercise of leg muscles as remedies for, 60; corrective exercises for, 223; consulting a specialist for, 223-224; means of detecting, 224-225; prevention of, 226.

Fleas, as spreaders of disease, 74.

Flesh eaters versus flesh abstainers, tests of, 197-199.

Fletcher, Horace, interest in mastication revived by, 46; experiment with method of, of thorough mastication, 200-209.

Flies, diseases carried by, 71; guarding against typhoid germs carried by, 73; methods of destroying, 73-74.

Focal infection, as a cause of disease, 81; diseases traceable to, 82; caution necessary in accepting principle too literally, 83; physical examinations to detect, 292.

Food, quantity of, 28; measurement of, by calories, 28; values of common foods, 29-30; the daily amount needed per person, 30; precautions regarding, in case of overweight, 32-33, 215-216; rules regarding, in case of underweight, 33, 219-220; diet in middle life, 33-34; diet in hot weather, 34; comparative amount needed by brain-workers, 34-35; eating when fatigued, 35; protein foods, 35-40; advantages of hard foods, 40-41; bulk a necessity in, 41-42, 148-150; objection to concentrated, 41; value of raw foods, 42; cooking necessary for some, 43; thorough mastication of, important, 44-47; enjoyment of, desirable, 46-47; choice of foods influenced by slow eating, 47; "good" and "bad" foods, 47-48; digestibility of so-called indigestible, 49; avoidance of fads as to, 50; consultation of physician regarding, 50; regulation of bowels by, 52; harmful preservatives and adulterants in, 65; comparative cost of, 129-131; drawbacks of civilization illustrated by, 148; soft and concentrated foods artificial, 148-150; the hurry habit and eating of, 150-151; misleading of appetites for, 151-152; tabular classification of common foods, 171; ideal proportion of the three elements in, 173; tabular list of values of, in daily diet, 175-183; relative energy value and cost of ready-to-serve foods, 184-190; minimal cost of, 190-194; calories consumed daily by different classes of workers, 195; experiments with mastication and instinctive eating, 200-209; references on, 209-211; negative value of alcohol as, 241-242.

Fowl, a high-protein food, 38; special objections to too great an amount of, 39.

France, consumption of alcohol in, 236; mortality statistics of, 286.

Franklin, Benjamin, views of, concerning colds, 124.

Fruit, to be eaten in middle life, 33; suitable for eating when fatigued, 35; cellulose supplied by fibrous, 41; vitamins supplied by, 42; acids supplied by, 43; among the best foods, 48; a laxative food, 52; value to teeth at end of a meal, 220.

Fruit acids, cleansing the mouth with, 86.

Fruits, table of food values of, 177, 179.

Fuel value, of common foods, 171, 175-183; of ready-to-serve foods, 184-190.

Galton, Sir Francis, identified with eugenic movement, 295.

Game as food, 48.

Games, for giving exercise, 95; advantages possessed by, as recreation, 99.

Garters, constriction from, 16.

Germany, consumption of alcohol in, 236. _See_ Prussia.

Germs, origin of colds in, 8-9, 70-71, 272; destroyed by sunlight, 14; clearing food of, 43; infections through, 69-78.

Gladstone, W. E., noted for mastication of food, 46.

Glucose, a cheap source of starch and sugar, 131.

Gonorrhea, sterilizing influence of, 78.

Grate fires as ventilators, 10.

Greeks, high ideals of ancient, 4; perfect physical poise depicted in sculptures of, 59; ideal of, in sports, 96.

Greens, laxative quality of, 52.

Grippe, avoidance of exposure to infection from, 70.

Guinea pigs, illustration from, of action of hereditary traits, 313-316.

Gums, cleansing the, 84-85.

Habits, as to defecation, 55; overcoming acquired, to lead a hygienic life, 134-135.

"Habitus enteroptoticus," posture called, 58.

Happiness, habit of, 115.

Hard foods, benefits of, 40-41.

Hats, ill effects of tight, 16.

Headache, sometimes caused by constipation, 51; sometimes due to a slouching posture, 57.

Health, present world-wide movement for conservation of, 2; influence of, on character, 105-107; mental rewards from, 107-108; influence of the mind on, 108-109; cost of good, 127-128; possibilities of attainment, 141-142.

Health foods and drinks, 3.

Heart, diseases of, due to focal infection, 82; common causes of troubles of, 90; effect of alcohol on, 240-241; effect of tobacco on, 250, 259-260, 263, 267; death rates from diseases of, 284, 285.

Heat, enervating effect of, 11.

Heating systems, ventilation and, 10-11.

Hens, influence of mind on health illustrated by, 108-109.

Heredity, dependence of health of individual on, 164-165; eugenic improvement attainable through control of, 293; discovery of laws of, resulting in science of eugenics, 293-294; traits influenced by, 297-298; distribution of traits, 298-300; desirable and undesirable traits, 300-301; illustrations of laws of, by Andalusian fowl and by guinea pigs, 307-316; application of principles to human race, 316-322.

Hill-climbing, as exercise, 94; for overweight, 217.

Hodge, Clifton P., fly-trap invented by, 73-74.

Home exercise, 94.

Hookworm disease, preventive measures, 75.

Hot weather, diet in, 34.

Houses, disadvantages attached to invention of, 145-147.

Housing, hygiene of, 7-14; disadvantages of the poor regarding, 128-129.

Humidity of air, how to secure, 11-12.

Hurry, habit of, in modern life, 114; as a promoter of indigestion, 150; excessive use of flesh foods due to, 151.

Hygiene, individual, ideals implied by, 1; medieval views contrasted with modern ideals, 1-2; good, ventilation the first rule, of, 7; mental, 105-118; unity of, 121-126; obstacles to, 126-135; possibilities of, 135-143; and civilization, 143-156; public versus individual, 157-159; necessity for cooperation between public and individual, 159-161; race, 163-168; of immediate concern to the present generation, while eugenics is important for future generations, 167-168.

Hypochondriacs, risk of becoming, 111.

Ice-cream, comparative food value of, 33.

Ideal food proportions, 173.

Ideals, of individual hygiene, 1; contrast afforded by medieval, 1-2; present-day establishment of more wholesome, 2; as to labor, 3-4; still further improvement needed in American, 4-6.

Idleness, evils of, 91.

Impairments, unsuspected physical, 136-139.

Inactivity, necessity for periods of, 89; rest and sleep the two great forms of, 89.

Indians, bad effects of indoor living upon, 146-147.

Indigestible foods, digestibility of so-called, 49.

Individual hygiene, public hygiene versus, 157-159; practice of, a remedy for degenerative tendencies, 292.

Indoor living, unnatural character and evils of, 145-147.

Industrial workers, unsuspected impairments among, 137-138; calories of food consumed daily by different classes of, 195; powers of, lessened by use of alcohol, 238, 244.

Infections of the body, by germs, 69-75; importance of cleanliness for avoiding, 75; through the mouth, 78-83; in colds, 272.

Infectious diseases, power of resistance to, weakened by alcohol, 68; results regarding, from teeth hygiene, 88.

Insect-borne diseases, 71.

Insomnia, remedial measures for, 102-103; often caused by excessive smoking, 264.

Instinctive eating, experiments with, 200-209.

Intestinal intoxication, distinguished from autointoxication, 81-82.

Intestinal poisoning, from insufficient mastication, 45.

Introspection, one of the curses of idleness, 91.

Iron, in vegetable foods, 40.

Italy, mortality statistics of, 286.

James, William, on enjoyment of life, 5; on religion of healthy-mindedness, 114.

Jews, effects of indoor living withstood by, 147.

Kidney, among the worst foods, 48.

Kidneys, death rates from diseases of, 284, 285.

Kipling, Rudyard, on concentrated foods, 41-42.

Labor, modern ideals concerning, 3-4; turned from drudgery into play by proper development of health ideals, 5-6; division of, an evil of civilization, 152. _See_ Work.

Lamb, food value of, 29, 178.

Laxative drugs, avoidance of, 53.

Laxative foods, 52.

Leg-lifting exercise for faulty posture, 222.

Lettuce, cellulose in, 41; vitamins supplied by, 42; food value of, 175.

Lice, diseases carried by, 74-75.

Life, no principle which limits, 142-143; shortening of, by unhygienic modes of living, 155.

Life Extension Institute, purpose of, 1.

Lighting, electric preferable to gas, 13.

Lime, deficiency of flesh foods in, 39.

Linen, use of, in clothing, 17.

Literature, avoidance of morbid, 99.

Liver, excess of acids produced by eating, 39; among the worst foods, 48.

Liver diseases, death rate from, 285.

London, expectation of life in, 289.

Lusk, Graham, quoted on minimal cost of food, 190-194; experiments by, to ascertain basal metabolism of body, 196.

Malaria, not caused by night air, 22; carried by mosquitoes, 71.

Marriage, effect of health on opportunities for, 2; exercising wisdom of choice in, 165-166; enactment of wise laws of, 167; science of eugenics and, 293-323.

Mastication, required by hard foods, 41; value of thorough, and evils of insufficient, 44-47; a desirable means of tooth and gum hygiene, 84; and mental attitude, 110; experiment to test effects of, on endurance and strength, 200-209.

Meat, decrease in amount eaten in middle life and in hot weather, 33-34; high-protein value of, 38; too much, a common error of diet, 38-39; excess of acids produced by, 39; endurance tests to ascertain value of, in diet, 197-199; sudden and complete exclusion from diet not desirable, 208; indulgence of craving for, 209.

Meats, table of food values of cooked, 178.

Mechanical diet indicator, 202.

Medical examination, desirable for determining one's diet, 50.

Medical practise, modern radical revolution in, 2-3.

Medieval indifference to matters pertaining to human body, 1-2.

Melancholy, physical sources of, 57, 105-106.

Mendel, discovery of laws of heredity by, 295.

Menstrual period in women, mental effects of, 106.

Mental condition, relation of mode of breathing to, 26-27; effect on sleep, 104-105; learning to avoid abnormal, 113.

Milk, food value of, 30, 181; protein value of human, 37; vitamins supplied by raw, 42; not cooked by pasteurization, 42-43; among the best foods, 48; pasteurizing, for avoiding typhoid germs, 73; skim milk a cheap source of protein, 131.

Mind, exercise of the, 97; activity and rest needed by, 105; serenity of, an important factor, 105; interrelation of health and, 105-118.

Mind-cure, proper and improper employment of, 111-112.

Mineral oils, as intestinal lubricants, 53.

Mineral waters, not to be used habitually, 53.

Minor ailments, as warning signals, 138-139.

Moistening of air, methods for, 12.

Monotony and interruption, 92.

Moore, R. M., quoted on mortality among abstainers and non-abstainers, 229.

Mortality. _See_ Death rate.

Mosquitoes, diseases communicated by, 22, 71; preventive measures against, 71-72.

Mouth, infection through the, 78-83; preventive measures against infection through, 83-88.

Moving pictures, eye-strain caused by, 93; hygienic value, in the way of recreation, 99.

Nasal congestion from overeating, 276.

Nasal douches, use of, 70, 276.

Nasal obstruction, a cause of colds, 272.

National Council of Safety, attitude toward alcohol, 244.

Nature, upsetting of equilibrium of, by civilized man, 143-156.

Neckwear, constriction from tight, 16.

Negroes, bad effects of indoor living upon, 146-147.

Nervous system, effect of alcohol on, 237-239.

Nervous troubles, outdoor treatment for, 21.

Neurasthenia, sometimes caused by a slouching posture, 57.

New York City, expectation of life in, compared with England and Wales, and London, 289.

New York State, death rate statistics of, 287, 288.

Nicotin, percentage of, in tobacco, 251-254; amount of, in tobacco smoke, 254-255, 260-261; effects of, 255-256; experiments with, on animals, 263.

Night air, mistaken ideas concerning, 22.

Nose, cleaning the, 70, 276-277.

Nuts, vitamins supplied by, 42; among the best foods, 48; digestibility of, when properly chewed, 49; table of food values of, 183.

Oatmeal, food value of, 29, 180.

Obstacles, to hygiene, 126-135.

Oils, as laxative food, 52; as intestinal lubricants, 53.

Oleomargarine, a cheap source of fat, 131.

Olive oil, a concentrated food, 28-29.

Olives, food value of, 30, 182.

Onions, cellulose in, 41; food value of, 176.

Oranges, food value of, 30, 177.

Outdoor living, benefits, of, 18-20, 276.

Outdoor schools, 19.

Outdoor sleeping, 20-24, 104.

Overeating, causes of, 154; nasal congestion from, 276.

Overheating of rooms, 11.

Overnourishment, from too free use of sugar, 48.

Overstrain, results of, 90; prevention of, 91-92.

Overweight, influence of, on longevity, 30-31; life insurance estimates as to, 31-32, 213; determination of, 31; importance of checking tendency to, 32; eating-habits that cause, 32-33; diet for, 215-216; fats to avoid, 216; exercise for, 217; main reliance to be placed on dietetic regulation rather than on exercise, 217; avoidance of sudden reduction in weight, 217-218; reduction of weight a simple matter, 218-219.

Overwork, popular delusions concerning, 124-125.

Pack, Fred. J., statistics by, on effects of tobacco, 256-259.

Paraffin oil, an intestinal lubricant, 53.

Parsnips, food value of, 41, 176.

Pasteurization, milk left uncooked by, 42-43.

Pastry, table of food values of, 179.

Patent medicines, habit-forming drugs in, 65.

Peanuts, food value of, 30, 183; digestibility of, 49; a cheap source of protein, 131.

Peas, a high-protein food, 38; protein in, a possible objection, 39-40.

Pecans, food value of, 30, 183.

Pepper, to be used sparingly, 48.

Peroxide of hydrogen, for disinfecting raw foods, 43.

Personal equation, hygienic living and the, 139-140.

Perspiration, benefits of, 76.

Philosophy, help to be obtained from, in field of mental hygiene, 114; Oriental superior to Occidental in training in control of attention, 115-116.

Physical examinations, a remedy for degenerative tendencies, 292.

Physiological effects of alcohol, 236-244.

Pickles, table of food values of, 182.

Pie, food value of, 29, 179.

Pillows, use of, in sleeping, 104.

Plague, spread by fleas and lice, 74-75.

Play, the halfway stage between work and rest, 100-101. _See_ Work and play.

Playgrounds, outdoor, 19.

Plays, hygienic value of, as recreation, 99.

Pneumonia, outdoor treatment for, 21; trend of death rate from, 285.

Poisons, from constipation, 51-56; relation of posture to, 57-64; habit-forming drugs and patent medicines, 65; substitution of milder for the more injurious, 65-66; alcohol, 67-68, 227-249; tobacco, 68-69, 250-271; infections with germs, 69-78; teeth and gums as a source of infection, 78-81; focal infection and autointoxication, 81-83.

Poor, disadvantages of the, in opportunities to live a healthy life, 128.

Posture, physical value of an erect, 57; breathing exercises for correcting evils of, 58; in standing and walking, 58-59; of the feet, 59-60; in sitting, 60-62; pains due to faulty, 62; effects of faulty, in children, 62; teaching of correct, 63; relation to character, 63-64; corrective exercises for faulty, 221-223; in cases of flat foot, 223.

Potatoes, food value of, 29, 176; valuable because of alkalinity, 43; among the best foods, 48; a cheap source of starch and sugar, 131; for underweight, 220.

Preservatives, harmful, 65.

Preventability of disease and death, 135-136.

Preventive dental treatment, 86-87.

Preventive medicine, practise of, 2-3; application of methods by people themselves, 3.

Program, constructing a day's, 120; main features of a eugenic, 167.

Prostitutes, disease among, 77.

Prostitution. _See_ Social evil.

Protein, function of, as a constituent of food, 35-36; examples of, 36; question of right proportion of, 36-37; common error of diet in using too much, 38; injuries from overabundance of, 38-39; poisoning caused by decomposition of, in the colon, 56; in cheap foods, 131; list of foods high, moderate and deficient in, 171; experiments to determine value of, in diet, 197-199.

Prunes, food value of, 30, 179; laxative quality of, 52.

Prussia, mortality statistics of, 286, 290-291.

Public hygiene, 157; what is included under, 157-158; progress made in, 158; various important measures of, 161-163.

Puddings, table of food values of, 179.

Pumpkins, cellulose in, 41.

Purins, in flesh food, leading to production of uric acid, 39; found in some vegetable foods, 40.

Pyorrhea, action of, 79-80; treatment for, 85-86.

Pyridin in tobacco smoke, 260-261.

Quack remedies, to be avoided in case of colds, 280.

Quacks and quack advertising, movement against, 162-163.

Quarantine, included in public hygiene, 158.

Quensel, Ulrik, on disagreement of work and alcohol, 244.

Quick lunches, an institution of civilization, 150; relative energy values and cost of different orders at, 184-190.

Quinine, use of, deleterious in case of colds, 280.

Race hygiene. _See_ Eugenics.

Races, effects of indoor living on different, 146-147; varied conditions in different, with respect to resistance to disease, 323.

Raw foods, value of, 42.

Reading, choice of, for recreation, 99.

Reading on trains, eye-strain caused by, 93.

Ready-to-serve foods, analysis and cost of, 184-190.

Recreation, outdoor, 19; necessity for, 89, 98; importance of enjoyment of, 98-99; forms of, 99; advantages possessed by games, 99; reading, dancing and card-playing, 99-100; suicidal amusements, 100.

Regime, demand for a well-balanced, 125-126.

Relatives, marriage of, 305-306.

Relaxation, cultivation of power of, 101; bathing a help to, 102.

Religion, as a help in field of mental hygiene, 114; of healthy-mindedness, 114-115.

Reproduction, rules of, under a eugenic program, 167.

Rest and sleep, the two great forms of inactivity, 89.

Rheumatism, traceable to focal infection, 82.

Rice, not a laxative food, 52; food value of, 180.

Richards, Mrs., on cost of food, 130.

Roosevelt Conservation Commission on National Vitality, report of, 136.

Rosenau, Dr., on sex instruction, 77.

Rowing-machine, home exercise on, 94.

Rubner, Prof., on injuries from overabundance of protein, 38-39.

Running, a beneficial exercise, 94.

Saccharin, harmful in foods, 65.

Salt, to be used sparingly, 48.

Salts, inorganic, in mixed diet, 43.

Sandals, benefits and risks in wearing, 17.

School, teaching correct posture in, 63.

Schools, outdoor, 19.

Segregation of defective classes, 321-322, 323.

Self-respect, relation between erect posture and, 63-64.

Serenity, to be practised as an art, 113.

Setting-up exercises, 221-224.

Sex hygiene, eugenics not limited to, 293-294.

Sex instruction, 77-78.

Shaler, N. S., "Man and the Earth," quoted, 143-144.

Shell-fish, a high-protein food, 38; special objections to too great an amount of, 39.

Shoes, care necessary in choosing proper, 16-17.

Shredded wheat biscuit, food value of, 29, 181.

Signal-station exercise, for faulty posture, 222.

Singing, as a hygienic practise, 26.

Sitting, correct posture in, 60-62.

Skim milk, a cheap source of protein, 131.

Skin training, establishing resistance to colds by, 273-274; means of, 274-275; by wearing light, porous clothing, 275.

Sleep, one of the two great forms of inactivity, 89; means of inducing, 102-103; importance of, to health, 103; hours of, 103; eating before, 103-104; use of pillows, 104; type of bed, 104; effect of mental attitude on, 104-105.

Sleeping, out-of-door, 3, 20-24, 104; a preventive of colds, 9, 276; for underweight, 220.

Sleeping porches, arrangement of, 22-23.

Sleeping tents, 23-24.

Social evil, remote causes of, 123; cooperation needed in movement against, 163.

Soups, food values of, 183.

Sour milk, among the best foods, 48; a means of reducing decomposition of protein in the colon, 56.

Specialists, medical, "one idea" doctrines of, 122.

Spinach, cellulose in, 41.

Spinal curvature, sometimes caused by faulty posture, 62.

Sponge-cake, food value of, 29, 179.

Squash, cellulose in, 41.

Standing, correct posture in, 58-59.

Starch, cheap sources of, 131.

Sterilization of defectives, 323.

Stevenson, R. L., on duty of being happy, 115.

Sugar, food value of, 30, 182; danger from overuse of, 48; cheap sources of, 131; taking of, for underweight, 220.

Sunlight, benefits of, to air, 14.

Sweden, American ideals of perfect manhood and womanhood inferior to those of, 4; attention to individual hygiene in, and decline in death rate, 159; mortality statistics of, 286, 292.

Sweetbreads, excess of acids produced by, 39; among the worst foods, 48.

Sweets, table of food values of, 182; time for taking, 220.

Swimming, as exercise, 94; an example of healthful activity and relaxation, 101-102; for overweight, 217.

Syphilis, destructive effect of, 78; resistance to, weakened by alcohol, 240.

Systemic injuries from mouth infection, 80-81.

Table, posture in sitting at a, 61.

Tea, degree of injury from, 66.

Teeth, benefits to, from hard foods, 41; evils of insufficient mastication, 44; infection from decayed, 78-83; danger from over-dentistried, 83; method of cleansing, 84-85; periodic examinations and cleanings, 86-87; question of saving, at expense of other parts of body, 87; correction of irregularities, 87-88; care of temporary, 88; results of teeth hygiene, 88; malformation of, a cause of nasal obstruction and colds, 272.

Temperature of living-rooms and work-rooms, 11.

Tents for outdoor sleeping, 23-24.

Thinking, exercise in, 97.

Thoughts, effect of character of, on sleep, 104-105.

Ticks, diseases spread by, 74.

Time, taking of, for hygienic living, 132-133.

Tobacco, injury from poison in, 65; ill effects of, 68-69; derivation of, 250-251; composition of, 251-255; effects on animals and on man, 255-265; increase in use of, 267-268; references concerning, 268-271.

Tobacco heart, risks accompanying, 263.

Tobacco smoke, air vitiation from, 13; amount of nicotin in, 254-255, 260-261.

Toeing out and toeing in, 60, 223.

Tomatoes, cellulose in, 41; vitamins supplied by, 42; food value of, 176.

Tongue, cleansing, with tooth-brush, 85.

Tooth powders and pastes, use of, 85.

Toxaemia, autointoxication distinguished from, 81-82.

Traits, subdivisibility of each individual into, according to Mendelian discovery, 295; rules resulting from inheritability of, 296; physical, known to act hereditarily, 297; mental, 297-298; moral, 298; laws governing inheritance of, 293; distribution of, 298-300; socially noble and ignoble, 300-301; mating of, in marriages, 304-305; maturing of, at certain ages, 306; dominant and recessive, 317-319; need of education on inheritability of, 323.

Tree-swaying exercise for faulty posture, 222.

Tuberculosis, outdoor sleeping as a remedy for, 21; sometimes produced by the "consumptive stoop," 57; infection from germs of, 71; remote causes of, 123; primarily a house disease, 146; liability of different races to, 147; public and individual hygiene invoked in fight against, 159; resistance to, weakened by alcohol, 240; trend of death rate from, 285; application of science of eugenics to, 299.

Typhoid fever, death rate from, 285.

Typhoid germs, guarding against, 72-73.

Typhus, carried by lice, 75.

Ulcer of the stomach, sometimes caused by focal infection, 82.

Underclothes, benefits of loose, porous, 14; suitable material for, 17.

Underweight, relation of, to longevity, 30-32; determination of, 31; remedy for, 33; life insurance statistics as to, 219; diet for, 219-220; exercise for, 220.

United Kingdom, consumption of alcohol in, 235, 236.

United States, consumption of alcohol in, 235, 236; trend of death rate in, 281-285; comparison of death rate with those of other countries, 286.

Unity of hygiene, 121-126.

Uric acid, caused by purins in diet, 39.

Urinary system, death rates from diseases of, 284, 285.

Vaccination, overcoming prejudice against, 163.

Vacuum cleaners, advantages of, 13.

Variety, need of, in work, 92.

Vegetables, bulky foods, 29; suitable diet for middle life, 33-34; objection to some, on account of richness in protein, 39-40; cellulose supplied by, 41; vitamins supplied by, 42; acids supplied by, 43; among the best foods, 48; laxative food, 52; table of food values of, 175-176.

Venereal diseases, infections from, 77-78; resistance to, weakened by alcohol, 240.

Ventilation, importance of, 7; motion, coolness, humidity, and freshness, of air chief features of, 7; overemphasis of danger from drafts, 8-9; by means of windows, 9; use of window-boards, 9-10; air-fans as a help in, 10; heating systems and, 10-11; importance of cool air and enervating effect of hot, 10-11; dryness and humidity of air, 11-12; relation of clothing to, 14-18; necessitated by conditions of civilization, 147; as a preventive of colds, 275.

Vermin, diseases spread by, 74-75.

Vertigo, causes of, 123.

Vital resistance, increased by outdoor sleeping, 21-22.

Vital surplus, conservation of, 5.

Vitamins in foods, 42; importance of well-being of body, 42.

Walking, correct posture in, 58-59; as exercise, 94; pleasures of, as recreation, 99; for overweight, 217.

Water, drinking, with meals, 48; varying effects of habits of drinking, on constipation, 52; freeing from typhoid germs, 72; importance of pure supply of, 162.

Water closets, height of seats of, 54.

Weak feet, causes of, 60; disturbances of health due to, 224; means of detecting, 224-225.

Weight, relation of, to longevity, 30-32; the correct average, 213-214; standards for, at various ages and heights, 214; avoidance of sudden reduction in, 217-218. _See_ Overweight _and_ Underweight.

Wheat-bran, a preventive of constipation, 52.

Whisky, not to be taken for colds, 280. _See_ Alcohol.

Wholesale costs of uncooked ingredients of standard foods, 192-193.

Will, exercise of the, 97-98; effort of, necessary to hygienic living, 126-127.

Window-boards, use of, 9-10.

Windows, best ventilation to be had through, 9.

Wood fires as ventilators, 10.

Woody fiber necessary in diet, 41.

Wool, use of, in clothing, 17.

Work, normal, one of the great blessings of life, 91; arrangement of hours for, 92; need of variety of, 92. _See_ Labor.

Work and play, the two great forms of activity, 89; adjusting the proportion of, 90.

Working conditions, disadvantages of the poor regarding, 128-129.

Worry, physical sources of, 105-106; physical effects of, 112; practising art of serenity as an offset to, 113; ailments aggravated by, 123.

Writer's cramp, cause of, 62.

Yard-arm exercise for faulty posture, 221-222.

Yellow fever, carried by mosquitoes, 71.

Zhebrovski, E. A., experiments of, with cigaret-smoking rabbits, 255.

+------------------------------------------------------------------+ | | | Transcriber's Note | | | | Three typographical errors have been corrected, and two missing | | endnote references inserted. Details of these can be found in | | the HTML version of this eBook. | | | | The inconsistent hyphenation of the words borderline, | | cooperation, coordination, cornstarch, healthymindedness, makeup | | and smallpox, and the inconsistent accenting of Beitraege, | | employes and regime has been left as in the original. | | | | The table on infant mortality was originally a further column on | | the large mortality table above it. This column has been | | separated to avoid scrollling and aid legibility. | | | +------------------------------------------------------------------+

End of Project Gutenberg's How to Live, by Irving Fisher and Eugene Fisk