CHAPTER XIX.

THE PHYSIOLOGY OF NUTRITION.

I HAVE repeatedly spoken of the nitrogenous and non-nitrogenous constituents of food, assuming that the nitrogenous are the more nutritious, are the plastic or flesh-building materials, and that the non-nitrogenous materials cannot build up flesh or bone or nervous matter, can only supply the material of fat, and by their combustion maintain the animal heat.

In doing so I have been treading on loose ground—I may say on a scientific quicksand. When I first taught practical physiology to children in Edinburgh, many years ago, this part of the subject was much easier to teach than now. The simple and elegant theory of Liebig was then generally accepted, and appeared quite sound.

According to this, every muscular effort is performed at the expense of muscular tissue; every mental effort, at the expense of cerebral tissue; and so on with all the forces of life. This consumption or degradation of tissue demands continual supplies of food for its renewal, and as all the working organs of the animal are composed of nitrogenous tissue, it is clearly necessary, according to this, that we should be supplied with nitrogenous food to renew them, seeing that the nitrogen of the air cannot be assimilated by animals at all.

But besides doing mechanical and mental work, the animal body is continually giving out heat, and its temperature must be maintained. Food is also demanded for this, and the non-nitrogenous food is the most readily combustible, especially the hydro-carbons or fats; the carbo-hydrates—starch, sugar, &c.—also, but in lower degree. These, then, were described as fuel food, or heat-producers.

This view is strongly confirmed by a multitude of familiar facts. Men, horses, and other animals cannot do continuous hard work without a supply of nitrogenous food; the harder the work the more they require, and the greater becomes their craving for it. On the other hand, when such food is eaten in large quantities by idle people, they become victims of inflammatory disease, or their health otherwise suffers, according, probably, to whether they assimilate or reject it.

Man is a cosmopolitan animal, and the variations of his natural demand for food in different climates affords very direct support to Liebig’s theory. Enormous quantities of hydro-carbon, in the form of fat, are consumed by the Esquimaux and by Europeans when they winter in the Arctic regions. They cannot live there without it. In hot climates _some_ fuel food is required, and the milder form of carbo-hydrates is chosen, and found to be most suitable; rice, which is mainly composed of starch, is an example. Sugar also. Offer an Esquimaux a tallow candle and a rice or tapioca pudding; he will reject the latter, and eat the former with great relish.

A multitude of other facts might be stated, all supporting Liebig’s theory.

There is one that just occurs to me as I write, which I will state, as it appears to have been hitherto unnoticed. Some organs which act in such wise that we can _see_ their mode of action are visibly disintegrated and consumed by their own activity, and may be seen to demand the perpetual renewal described by Liebig. There are glands of cellular structure which cast off their terminal cells containing the fluid they secrete; do their work by giving up their own structural substance at their peripheral working surface.

Where, then, is the quicksand? It is here. If muscular and mental work were done at the expense of the nitrogenous muscular and cerebral tissues, the quantity of nitrogen excreted should vary with the amount of work done. This was formerly stated to be the case without hesitation, as the following passage from Carpenter’s ‘Manual of Physiology’ (3rd edition, 1856, page 256), shows: ‘Every action of the nervous and muscular systems involves the death and decay of a certain amount of the living tissue, as is indicated by the appearance of the products of that decay in the excretions.’

More recent experiments by Fick and Wislicenus, Parkes, Houghton, Ranke, Voit, Flint, and others are said to contradict this by showing that the waste nitrogen varies with the quantity of nitrogenous food that is eaten, but not with the muscular work done. For the details of these experiments I must refer the reader to standard _modern_ physiological treatises, as a full description of them would carry me too far away from my immediate subject. (Dr. Pavy’s ‘Treatise on Food’ has an introductory chapter on ‘The Dynamic Relations of Food,’ in which this subject is clearly treated in sufficient detail for popular reading.)

It is quite the fashion now to rely upon these later experiments; but for my own part, I am by no means satisfied with them—and for this reason, that the excretions from the skin and from the lungs were not examined.

It is just these which are greatly increased by exercise, and their normal quantity is very large, especially those from the skin, which are threefold, viz. the insensible perspiration, which is transpired by the skin as invisible vapour; the sweat, which is liquid, and the solid particles of exuded cuticle.

Lavoisier and Seguin long ago made very laborious experiments upon themselves in order to determine the amount of the insensible perspiration. Seguin enclosed himself in a bag of glazed taffeta, which was tied over him with no other opening than a hole corresponding to his mouth; the edges of this hole were glued to his lips with a mixture of turpentine and pitch. He carefully weighed himself and the bag before and after his enclosure therein. His own loss of weight being partly from the lungs and partly from the skin, the amount gained by the bag represented the quantity of the latter; the difference between this and the loss of his own weight gave the amount exhaled from the lungs.

He thus found that the largest quantity of _insensible_ exhalation from the lungs and skin together amounted to 3½ oz. per hour, or at the rate of 5¼ lbs. per day. The smallest quantity was 1 lb. 14 oz., and the mean was 3 lbs. 11 oz. Three-fourths of this was cutaneous.

These figures only show the quantity of insensible perspiration during repose. Valentin found that his hourly loss by cutaneous exhalation while sitting amounted to 32·8 grammes, or rather less than 1¼ oz. On taking exercise, with an empty stomach, in the sun, the hourly loss increased to 89·3 grammes, or nearly three times as much. After a meal followed by violent exercise, with the temperature of the air at 72° F., it amounted to 132·7 grammes, or nearly 4½ times as much as during repose. A robust man, taking violent exercise in hot weather, may give off as much as 5 lbs. in an hour.

The third excretion from the skin, the epithelial or superficial scales of the epidermis, is small in weight, but it is solid, and of similar composition to gelatin. It should be understood that this increases largely with exercise. The practice of sponging and ‘rubbing down’ of athletes removes the excess; but I am not aware of any attempt that has been made to determine accurately the quantity thus removed.

Does the skin excrete nitrogenous matter that may be, like urea, a product of the degradation or destruction of muscular tissue?

The following passage from Lehmann’s ‘Physiological Chemistry’ (vol. ii. p. 389), shows that the skin throws out plenty of nitrogen obtained from somewhere: ‘It has been shown by the experiments of Milly, Jurine, Ingenhouss, Spallanzani, Abernethy, Barruel, and Collard di Martigny, that _gases_, and especially _carbonic acid_ and _nitrogen_, are likewise exhaled with the liquid secretion of the sudiparious glands. According to the last-named experimentalist the ratio between these two gases is very variable; thus, in the gas developed after vegetable food there is a preponderance of carbonic acid, and, after animal food, there is an excess of nitrogen. Abernethy found that on an average the collective gas contained rather more than two-thirds of carbonic acid and rather less than one-third of nitrogen.’ But it appears that less gas is exhaled when there is much liquid perspiration.

Lehmann’s summary of the experiments of Abernethy, Brunner, and Valentin (vol. ii. p. 391), gives the amount of hourly exudation, under ordinary circumstances, as 50·71 grammes of water, 0·25 of a gramme of carbon, and 0·92 of a gramme of nitrogen. This amounts to 21½ grammes of nitrogen per day in the _insensible_ perspiration; three-quarters of an ounce avoirdupois, or as much nitrogen as is contained in one pound and a half of natural living muscle.

That the liquid perspiration contains compounds of nitrogen, and just such compounds as would result from the degradation of nitrogenous tissue, is unquestionable. As Lehmann says (vol. ii. p. 389), ‘the sweat very easily decomposes, and gives rise to the secondary formation of ammonia.’ Simon and Berzelius found salts of ammonia in the sweat: that the ammonia is combined both with hydrochloric acid and with organic acids: that it probably exists as carbonate of ammonia in alkaline sweat.

The existence of urea in sweat appears to be uncertain; some chemists assert its presence, others deny it. Favre and Schottin, for example, who have both studied the subject very carefully, are at direct variance. I suspect that both are right, as its presence or absence is variable, and appears to depend on the condition of the subject of the experiment.

Favre describes a special nitrogenous acid which he discovered in sweat, and names it _hydrotic_ or _sudoric acid_. Its composition corresponds, according to his analysis, to the formula C_{10}H_{8}NO_{13}.

I have summarised these facts, as they show clearly enough that conclusions based on an examination of the quantity of nitrogen excreted by the kidneys alone (and such is the sole basis of the modern theories), are of little or no value in determining whether or not muscular work is accompanied with degradation of muscular tissue. The well known fact that the total quantity of excretory work done by the skin increases with muscular work, while that from the kidneys rather diminishes, indicates in the plainest possible manner that an examination of the skin secretion should be primary in connection with this question. To entirely neglect this in such a research is a scientific parallel to the histrionic feat of performing the tragedy of ‘Hamlet’ with the Prince of Denmark omitted.

Seeing that it has been entirely neglected, I am justified in expressing, very plainly and positively, my opinion of the worthlessness of all the modern research upon which the alleged refutation of Liebig’s theory of the destruction and renewal of living tissue in the performance of vital work is based, and my rejection of the modern alternative hypothesis concerning the manner in which food supplies the material demanded for muscular and mental work.

I may be accused of rashness and presumption in thus attempting to stem the overwhelming current of modern scientific progress. Such, however, is not the case. It is modern scientific _fashion_, rather than scientific _progress_, that I oppose. We have too much of this millinery spirit in the scientific world just now; too much eagerness to run after ‘the last thing out,’ and assume, with undue readiness, that the ‘latest researches’ are, of course, the best—especially where fashionable physicians are concerned.

Having summarised Liebig’s theory of the source of vital power, and its supposed refutation by modern experiments, I will now endeavour to state the alternative modern hypothesis, though not without difficulty, nor with satisfactory result, seeing that the recent theorists are vague and self-contradictory. All agree that vital power or liberated force is obtained at the expense of some kind of chemical action of a destructive or oxidising character, and is, therefore, theoretically analogous to the source of power in a steam-engine; but when they come to the practical question of the demand for working fuel or food, they abandon this analogy.

Pavy says (‘Treatise on Food and Dietetics,’ page 6): ‘In the liberation of actual force, a complete analogy may be traced between the animal system and a steam-engine. Both are media for the conversion of latent into actual force. In the animal system, combustible material is supplied under the form of the various kinds of food, and oxygen is taken in for the process of respiration. From the chemical energy due to the combination of these, force is liberated in an active state; and, besides manifesting itself as heat, and in other ways peculiar to the animal system, is capable of performing mechanical work.’ In another place (page 59 of same work), after describing Liebig’s view, Dr. Pavy says: ‘The facts which have been already adduced’ (those above described on the nitrogen eliminated by the kidneys), ‘suffice to refute this doctrine. Indeed, it may be considered as abundantly proved that food does not require to become organised tissue before it can be rendered available for force-production.’ On page 81 he says: ‘While nitrogenous matter may be regarded as forming the essential basis of structures possessing active or living properties, _the non-nitrogenous principles may be looked upon as supplying the source of power_. The one may be spoken of as holding the position of the instrument of action, while the other supplies the motive power. Nitrogenous alimentary matter may, it is true, by oxidation contribute to the generation of the moving force, but, as has been explained, in fulfilling this office there is evidence before us to show that it is split up into two distinct portions, one containing _the nitrogen, which is eliminated as useless, and a residuary non-nitrogenous portion which is retained and utilised in force-production_.’

The italics are mine, for reasons presently to be explained. Pavy’s work contains repetitions and further illustrations of this attribution of the origin of force to the non-nitrogenous elements of food.

Then we have a statement of the experiments of Joule on the mechanical equivalent of heat, connected with experiments of Frankland with the apparatus that is used for determining the calorific value of coal, &c.—viz. a little tubular furnace charged with a mixture of the combustible to be tested, and chlorate of potash. This being placed in a tube, open below, and thrust under water, is fired, and gives out all its heat to the surrounding liquid, the rise of temperature of which measures the calorific value of the substance (see fig. 7, page 21, ‘Simple Treatise on Heat’).

From this result is calculated the mechanical work obtainable from a given quantity of different food materials. That from a gramme is given as follows:

Beef fat 27,778 } Units of work, Starch (arrowroot) 11,983 } or number of Lump sugar 10,254 } pounds lifted Grape sugar 10,038 } one foot.

In Dr. Edward Smith’s treatise on ‘Food,’ the foot-pound equivalent of each kind of food is specifically stated in such a manner as to lead the student to conclude that this represents its actual working efficiency _as food_. Other modern writers represent it in like manner.

Here, then, comes the bearing of these theories on my subject. A practical dietary or _menu_ is demanded, say, for navvies or for athletes in full work; another for sedentary people doing little work of any kind.

According to the new theory, the best possible food for the first class is fat, butter being superior to lean beef in the proportion of 14,421 to 2,829 (Smith), and beef fat having nearly eight times the value of lean beef. Ten grains of rice give 7,454 foot-pounds of working-power, while the same quantity of lean beef gives only 2,829; according to which 1 lb. of rice should supply as much support to hard workers as 2½ lbs. of beefsteak. None of the modern theorists dare to be consistent when dealing with such direct practical applications.

I might quote a multitude of other palpable inconsistencies of the theory, which is so slippery that it cannot be firmly grasped. Thus, Dr. Pavy (page 403), immediately after describing bacon fat as ‘the most efficient kind of force-producing material,’ and stating that ‘the _non-nitrogenous_ alimentary principles appear to possess a higher dietetic value than the _nitrogenous_,’ tells us that ‘the performance of work may be looked upon as necessitating a _proportionate supply_ of _nitrogenous_ alimentary matter,’ and his reason for this admission being that such nitrogenous material is required for the nutrition of the muscles themselves.

A pretty tissue of inconsistencies is thus supplied! Non-nitrogenous food is the best force-producer—it corresponds to the fuel of the steam-engine; the nitrogenous is necessary only to repair the machine. Nevertheless, when force production is specially demanded, the food required is not the force-producer, but the special builder of muscles, the which muscles, according to theory, are _not_ used up and renewed in doing the work.

It must be remembered that the whole of this modern theoretical fabric is built upon the experiments which are supposed to show that there is no more elimination of nitrogenous matter during hard work than during rest. Yet we are told that ‘the performance of work may be looked upon as necessitating a proportionate supply of nitrogenous alimentary matter,’ and that such material ‘is split up into two distinct portions, one containing the nitrogen, which is eliminated as useless.’ This thesis is proved by experiments showing (as asserted) that such elimination is not so proportioned.

In short, the modern theory presents us with the following pretty paradox. The consumption of nitrogenous food is proportionate to work done. The elimination of nitrogen is _not_ proportionate to work done. The elimination of nitrogen _is_ proportionate to the consumption of nitrogenous food.

I have tried hard to obtain a rational physiological view of the modern theory. When its advocates compare our food to the fuel of an engine, and maintain that its combustion _directly_ supplies the moving power, what do they mean?

They cannot suppose that the food is thus oxidised as food, yet such is implied. The work cannot be done in the stomach, nor in the intestinal canal, nor in the mesenteric glands, nor in their outlet, the thoracic duct. After leaving this, the food becomes organised living material, the blood being such. The question, therefore, as between the new theory and that of Liebig, must be whether work is effected by _the combustion of the blood itself_ or by the degradation of the working tissues, which are fed and renewed by the blood. Although this is so obviously the only rational physiological question, I have not found it thus stated.

Such being the case, the supposed analogy to the steam-engine breaks down altogether; the food is certainly assimilated, is converted into the living material of the animal itself before it does any work, and therefore it must be the wear and tear of the machine itself which supplies the working power, and not that of the food as mere fuel material shovelled directly into the animal furnace.

I thus agree with Playfair, who says that the modern theory involves a ‘false analogy of the animal body to a steam-engine,’ and that ‘incessant transformation of the acting parts of the animal machine forms the condition for its action, while in the case of the steam-engine it is the transformation of fuel external to the machine which causes it to move.’ Pavy says that ‘Dr. Playfair, in these utterances, must be regarded as writing behind the time.’ He may be behind as regards the _fashion_, but I think he is in advance as regards the _truth_.

My readers, therefore, need not be ashamed of clinging to the old-fashioned belief that their own bodies are alive throughout, and perform all the operations of working, feeling, thinking, &c., by virtue of their own inherent self-contained vitality, and that in doing this they consume their own substance, which has to be perpetually replaced by new material, its quality depending upon the manner of working and the matter and manner of replacement.

The course of our own evolution thus depends upon ourselves; we may, according to our own daily conduct, be building up a better body and a better mind, or one that shall be worse than the fair promise of the original germ. Therefore the philosophy of the preparation of the material of which the body and brain are built up and renewed must be worthy of careful study. This philosophy is ‘THE CHEMISTRY OF COOKERY.’

INDEX.

ACIDS, mineral and vegetable, 224

Aërated bread, 206

Albumen, 19 coagulation of, 20 of flesh, 24 loss of in boiling fish and meat, 24

Allotropism, 88

Alum in bread, 203

Animal diastase, 186

Apple fritters, 101

Argol, 273

Arrowroot, 179

Arsenic eating, 256

BAIN-MARIE, 22, 119

Baked meat, prejudice against, 64

Baking _versus_ roasting of meat, 65

Barley sugar, 88

Basting, 57

Bavarian beggars and Count Rumford, 229

Birds’-nests, edible, 35

Blood-fibrin, 43

‘Boiled meat’ is not boiled, 14

Boiling of fat, 84 of water, 8

Bone-soup Commission of French Academy, 36

Borized meat, 170 milk, 171

Bosch _v._ butter, 167 _v._ butterine, 144

Boussingault’s experiments on bread, 207

Bread, 197

British gum, 182

Browning of roasted meat, 78 rationale of, 87

Budrum, 310

Butter, 163 and infection, 166

CALCAREOUS WATER, 10

Cancer and flesh eating, 301

Caramel, 87-89 a disinfectant, 92

Carnivorous, a sheep, 301

Casein, 127 changes of, 128 vegetable, 211

Cayenne pepper, 260

Cellular tissue, 174, 180

Cheese, cookery of, 136 digestibility of, 135 in soup, 149 nutritive value of, 131 phosphates in, 133 porridge, 151 pudding, 136 solubility of, 143

Chemical analysis and nutritive value of food, 6

Chinese and cooked water, 13

Chitin, 33

Chondrin, 33

Cocoa, 261

‘Coffee as in France,’ 96

Colloids and crystalloids, 115

Composition of albumen, gelatin, and fibrin, 45 kreatine and kreatinine, 46

Condensed milk, 129

Condiments, 259

Convection in roasting, 49

Cooked water, 10

Cream, 162

Crust of bread, 91, 136, 200

Curd of milk, 127

DEXTRIN, 182, 185 in bread, 200

Diastase, 184, 303

Diastased porridge, 305, 306, 311, 312

Difference between vegetable and animal food, 177, 297

Diffusion of liquids, 112

Digestion of starch, 186

Dinner of a French or Swiss peasant, 126

Diosmosis, 114

Disinfection of water by boiling, 12 by toast, 92

Dissociation of flavours, 49

Dolby’s extractor, 120

Domestic chops and steaks, 52

Dough, 197

Dripping, 159

Drunkenness and cookery, 61

ECONOMICAL FRYING, 98

Effects of diastased porridge, 311

Eggs, cookery of, 22 nutritive value of, 19 of feathered and featherless young birds, 20

Endosmosis and exosmosis, 114

English stewing, 124

Ensilage of human food, 214 by means of diastase, 308

Excretion of nitrogen from the skin, 316

Expansion of well-grilled meat, 53

Experiment with Rumford’s roaster, 74

Explosion of water, 86

Extract of meat, 117

FAT, 156 action of heat on, 84, 158 bath for joints, 57 for frying, 101

Fermentation of bread, 198

Ferments, 184

Fibrin, 43

Fish, boiling of, 24, 27 cooked in paper, 60 roasting, 58 with cheese, 153

Flames, different kinds of, and grilling, 51

Flavouring power of the juices of meat, 26

Flesh feeding, a temporary barbarism, 7

Flummery, 310

Fondu, 136

Forces of nature co-operating with man, 2

Frozen meat, 94, 168

Fruit jelly, 225

Frying, 84 kettle, 98 theory of, 97

Fuel wasted in boiling, 15

GASTRIC JUICE, modification of, 44

Gelatin, fibrin, and the juices of meat, 32 hydration of, 41 solubility of, 32

Gluten, 194 fibrin and gluten casein, 195

Glycerine, 157

Green-pea clear soup, 219

Grilling of chops and steaks, 52

Gum arabic, 183

HASTY PUDDING AND CHEESE, 152

Hot rolls from stale bread, 208

Hydration of gelatin, 41 of starch, 181

INCRUSTATION OF BOILERS, kettles, &c., 11

Isinglass, 36, 41

Italian cookery, 90 of cheese, 149

JOHNSTON ON TEA AND COFFEE, 251

Juices of meat, 25, 40, 45

KITCHEN A CHEMICAL LABORATORY, the, 4

Kitchener-ovens and roasters, 7

Kreatine and kreatinine, 45

LARD, 159 dissociation of, 85

Leaven, 206

Leg of mutton, how to boil, 26

Legumin, 212

Lehmann on coffee, 251

‘Liaison au roux,’ 90

Liebig on gelatin, 36 on tea and coffee, 251

Liebig’s extract of meat, 25, 37

Lignin, 174

Lime in bread, 205

Lobster suppers, 33

Locusts as food, 34

MACERATION, 112

Magnesia in bread, 265

Malt, action on various foods, 305 directions for using, 306, 312

Malted food, 303

Man, the cooking animal, 295

Man’s work on earth, 1

Marie Antoinette’s pie-crust, 176

Milk, a carrier of infection, 164 composition of, 162 cooking of, 163 dietetic value of, 161 for herbivora, carnivora, and man, 296 supply to London, 163

Muscle fibrin, 43

NEW AND STALE BREAD, 207

Nitrogenous principles of plants and animals compared, 195

Norwegian cooking apparatus, 24, 30

Nutrition, fashionable theory of, 315 inconsistencies of fashionable theory of, 319 Liebig’s theory of, 313 Playfair on the physiology of, 324 the physiology of, 313

Nutritive value of food as affected by cookery, 6 of gelatin, 36

ŒNANTHIC ETHER, 270

Oils for frying, 107 volatile and fixed, 84

Old hens, how to roast, 125, 126

Oleomargarine, 146

Oven, construction of, 80

Oysters and invalids, 180

PARMESAN CHEESE, 151, 220

Pasteuring of wine, 269

Peasants’ food in Italy and France, 61, 126

Pease-pudding, 214-218

Pectin, 225

Penny dinners, 244

Phosphates in milk and cheese, 133

Phosphorus in bones and brain, 134

Popped corn, 210

Porridge _v._ flesh, 299

Potage and stewed meat, 116 value of, 219

Potash bitartrate, solubility of, 272 food, 221 in cheese cookery, 141 in potatoes, 190 scurvy, gout, &c., 142

Potatoes in bread, 202 a curse of Ireland, 193 and cheese porridge, 152 and scurvy, 190 cookery of, 189 nutritive value of, 192

Purification of fat, 101

RADIATION AND CONVECTION IN ROASTING, 49 in grilling, 47

Rahat Lakoum, 225

Rationale of roasting, 48

Reaction from tea, 257

Rennet, 129

Rice and cheese, 153

‘Risotto à la Milanese,’ 150

Roasting an ox, 56 and grilling, 47 before open fire, evils of, 60 large joints, 55 small joints, 53

Rumford, Count of, 5 on boiling meat, 16 on military rations, 241 on the pleasure of eating, 238

Rumford’s cookery, 227

Rumford’s experiment on low temperature roasting, 29 roaster, 63, 70 roasting oven, 76 soup, 231 soup compared with flesh food, 298

SAGO, 189

Saliva and diastase, 304

Salivary diastase, 186

Salmon cooking in Norway, 28

Samp, 240

Sauer-kraut, 216

Sawdust as food, 175

Science in the kitchen, 4

Seeds as food, 194

Sheep, a carnivorous and cannibal, 301

Sherbet, 225

Shrimps, fried, 34

Simmering and boiling, 14

Small joints and their cookery, 53

Smith, Dr., on tea, 254

Snail soup, 35

Soluble and insoluble casein, 130

Solution of vegetable casein, 217

South Kensington food exhibits, 211

Sowans, 310

Specific sapidity of food, 239

Spinning of sugar, 89

Starch, 178, 181

Stearic acid, 157

Stewing, 111 and albumen, 119

Stirabout and cheese, 153

Sulphate of copper in bread, 205

Super-heaters, cost of, 75

Syntonin, 43

TAPIOCA, 188

Tea and coffee, Rumford’s substitute for, 245 physiological action of, 246

Technical and technological education, 3

Temperature for stewing, 118 of vegetable cookery, 177

Tenderness, true and false, 121

Testing the temperature of fat bath, 100

Thermometers for the kitchen, 79 for fat bath, 105

Thomson, Sir Henry, on roasting of fish, 58

Tinned meat, 121

Toast and water, 92

Tripe and cheese, 154

UNFERMENTED BREAD, 200

VAPOURS OF ROASTING MEAT, 78

Vegetable casein, 211 diet, economy of, 301 fibrin, casein and gluten, 195 food and mixed diet compared, 297 juices, 211 -marrow _au gratin_, 155 tissue, 173

Vegetables, the cookery of, 173

Vegetarian question, the, 294

WARREN’S COOKING-POT, 81

Waste of fuel in boiling, 15

Water-bath cookery, 119

Water in fish, 86

Whole-meal bread, 6, 204

Wine, artificial bouquet of, 291 artificial colour of, 288 bouquet of, 288 cookery of, 265 cost of, 265-292 drying of, 280 natural colour of, 288 Pasteuring of, 269 plastering of, 277 sickness of, 271 sulphuric acid in, 276

YOLK OF EGG, ITS COAGULATION, 23

_Spottiswoode & Co. Printers, New-street Square, London._

* * * * *

Transcriber’s Notes:

Obvious punctuation errors repaired. Larger vulgar fractions had been printed with a hyphen instead of a slash. This was changed to a slash for conformity. (1-30th is now 1/30th)

Page 54, “is” changed to “it” (exposed, it is evident)

Page 81, “judgment” changed to “judgement” (the judgement of which)

Page 108, while it seems that this sentence is missing an object:

When common sense and true sentiment supplant mere unreasoning prejudice, vegetable oils and vegetable fats will largely supplant those of animal origin in every element of our dietary.

It has been quoted in just that manner across numerous publications.

Page 109, “facts” changed to “fats” (the chemistry of fats)

Page 328, the text refers to the now more usually spelled “sauerkraut” as “sour-kraut” in the text and “Sauer-kraut” in the index. These usages were retained as printed.

Page 328, “fath” changed to “fat” (for fat bath)

End of Project Gutenberg's The Chemistry of Cookery, by W. Mattieu Williams