Chapter 8

Surgical cleanliness differs from the housewife's idea of cleanliness in that its details seem frivolous, because it aims at the removal of microscopic particles. Stains, such as housewives abhor, if germ-free, are not objected to in surgery.

The hands and arms, and especially the finger nails, of the surgeon, assistants, and nurses should be well scrubbed with hot water and soap, by means of a nail brush, immediately before the operation. The patient's body about the site of the proposed operation should be similarly scrubbed with a brush and cleanly shaved. Subsequently the hands of the operator, assistants, and nurses, and the field of operation should be immersed in, or thoroughly washed with, corrosive sublimate solution (1:1,000 or 1:2,000). Finger rings, bracelets, bangles, and cuffs worn by the surgeon, assistants, or nurses must be removed before the cleansing is begun; and the clothing covered by a clean white apron, large enough to extend from neck to ankles and provided with sleeves.

The instruments should be similarly scrubbed with hot water and soap, and all particles of blood and pus from any previous operation removed from the joints. After this they should be immersed for at least fifteen minutes in a solution of beta-naphthol (1:2,500), which must be sufficiently deep to cover every portion of the instruments. After cleansing the instruments with soap and water, baking in a temperature a little above the boiling point of water is the best sterilizer. During the operation the sterilized instruments should be kept in a beta-naphthol solution and returned to it when the operator is not using them.

[The antiseptic solutions mentioned here are too irritating for use in operations within the abdomen and pelvis. Water made sterile by boiling is usually the best agent for irrigating these cavities, and for use on instruments and sponges. The instruments and sponges must be previously well sterilized.]

Sponges should be kept in a beta-naphthol or a corrosive sublimate solution during the operation. After the blood from the wound has been sponged away, they should be put in another basin containing the antiseptic solution, and cleansed anew before being used again. The antiseptic sutures and ligatures should be similarly soaked in beta-naphthol solution during the progress of the operation.

No one should touch the wound but the operator and his first assistant. No one should touch the sponges but the operator, his first assistant, and the nurse having charge of them. No one should touch the already prepared ligatures or instruments except the surgeon and his first or second assistants.

None but those assigned to the work are expected to handle instruments, sponges, dressings, etc., during the operation.

When any one taking part in the operation touches an object not sterilized, such as a table, a tray, or the ether towel, he should not be allowed to touch the instruments, the dressings, or the ligatures until his hands have been again sterilized. It is important that the hands of the surgeon, his assistants, and nurses should not touch any part of his own body, nor of the patient's body, except at the sterilized seat of operation, because infection may be carried to the wound. Rubbing the head or beard or wiping the nose requires immediate disinfection of the hands to be practiced.

The trailing ends of ligatures and sutures should never be allowed to touch the surgeon's clothing or to drag upon the operating table, because such contact may occasionally, though not always, pick up bacteria which may cause suppuration in the wound.

Instruments which fall upon the floor should not be again used until thoroughly disinfected.

The clothing of the patient, in the vicinity of the part to be operated upon, and the blanket and sheets used there to keep him warm, should be covered with dry sublimate towels. All dressings should be kept safe from infection by being stored in glass jars, or wrapped in dry sublimate towels.

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INFLUENCE OF REPOSE ON THE RETINA.

Some interesting researches have lately been published in an Italian journal concerning the influence of repose on the sensitiveness of the retina (a nervous network of the eye) to light and color. The researches in question--those of Bassevi--appear to corroborate investigations which were made some years ago by other observers. In the course of the investigations the subject experimented upon was made to remain in a dark room for a period varying in extent from fifteen to twenty minutes. The room was darkened, it is noted, by means of heavy curtains, through which the light could not penetrate. After the eyes of the subject had thus been rested in the darkness, it was noted that the sensitiveness of his sight had been increased threefold. The mere sense of light itself had increased eighteen times. It was further noted that the sensitiveness to light rays, after the eye had been rested, was developed in a special order; the first color which was recognized being red, then followed yellow, while green and blue respectively succeeded. If color fatigue was produced in the eye by a glass of any special hue, it was found that the color in question came last in the series in point of recognition. The first of these experiments, regarded from a practical point of view, would appear to consist in an appreciation of the revivifying power of darkness as regards the sight. The color purple of the retina is known to become redeveloped in darkness; and it is probable, therefore, that the alternation of day and night is a physical and external condition with which the sight of animals is perfectly in accord.

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SUN DIALS.

An article on the subject, recently published by us, has gained for us the communication of two very interesting sun dials, which we shall describe. The first, which we owe to the kindness of General Jancigny, is of the type of the circular instrument, of which we explained the method of using in our preceding article. The hour here is likewise deduced from the height of the sun converted into a horary angle by the instrument itself; but the method by which such conversion operates is a little different. Fig. 1 shows the instrument open for observation. We find here the meridian circle, M, and the equator E, of the diagram shown in Fig. 3 (No. 4); but the circle with alidade is here replaced by a small aperture movable in a slide that is placed in a position parallel with the axis of the world. Upon this slide are marked, on one side, the initials of the names of the months and on the other side the corresponding signs of the zodiac. The sun apparently describing a circle around the axis, PP¹, the rays passing through a point of the axis (small aperture of the slide) will travel over a circular cone around such axis. If, then, the apparatus be so suspended that the circle, M, shall be in the meridian, the slide parallel with the earth's axis, and the circle, E, at right angles with the slide, the pencil of solar light passing through the aperture will describe, in one day, a cone having the slide for an axis; that is to say, concentric with the equator circle. If, moreover, the aperture is properly placed, the luminous pencil will pass through the equator circle itself; to this effect, the aperture should be in a position such that the angle, a (Fig. 3, No. 4), may be equal to the declination of the sun on the day of observation. It is precisely to this end that the names of the months are inscribed upon the slide....

The accessories of the instrument are as follows: A ring with a pivot for suspending the meridian circle, and the position of which, given by a division in degrees marked upon this circle, must correspond with the latitude of the place; two stops serving to fix the position of the equator circle; finally the latitude of various cities. The instrument was constructed at Paris, by Butterfield, probably in the last quarter of the eighteenth century.

The second instrument, which is of the same nature as the cubical sun dial--that is to say, with horary angle--is, unlike the latter, a true trinket, as interesting as a work of art as it is as an astronomical instrument. It is a little mandolin of gilded brass, and is shown of actual size in Fig. 2. The cover, which is held by a hook, may be placed in a vertical position, in which it is held by a second hook. It bears in the interior the date 1612. This is the only explicit historic datum that this little masterpiece reveals to us. Its maker, who was certainly an artist, and, as we shall see, also a man of science, had the modesty not to inscribe his name in it.

No. 2 of Fig. 3 represents the instrument open. It rests upon the tail piece and neck of the mandolin. The cover is exactly vertical. The bottom of the mandolin is closed by a horizontal silver plate, beneath which is soldered the box of a compass designed to put the instrument in the meridian, and carrying upon its face an arrow and the indications S. OR. M. OC., that is to say, "Septentrion" (north), "Orient" (east), "Midi" (south), "Occident" (west). One of the ends of the needle of the compass is straight, while the other is forked. It is placed in a position in which it completes the arrow, thus permitting of making a very accurate observation (Fig. 2, No. 3). Around the compass, the silver plate carries the lines of hours. It is perfectly adjusted, and held in place by a screw that traverses the bottom of the instrument. In front of the compass it contains a small aperture designed to permit of the passage of the indicating thread, which, at the other end, is fastened to the cover. The silver plate is not soldered, in order that the thread may be replaced when it chances to break. On the inner part of the cover are marked in the first place the horary lines, traversed by curves that are symmetrical with respect to the vertical and having the aspect of arcs of hyperbolas. At the extremity of these lines are marked the signs of the zodiac. At the top, a pretty banderole, which appears at first sight to form a part of the _ensemble_ of the curves, completes the design. Such is this wonderful little instrument, in which everything is arranged in harmonious lines that delight the eye and easily detract one's attention from a scientific examination of it. Let us enter upon this drier part of our subject; we shall still have room to wonder, and let us take up first the higher question.

Let us consider a horizontal plane (Fig. 3, No. 2)--a plane perpendicular to the meridian, and a right line parallel with the axis of the world. Let P be a point upon this line. As we have seen, such point is the summit of a very wide cone described in one day by the solar rays. At the equinox this cone is converted into a plane, which, in a vertical plane, intersects the straight line A B. Between the vernal and autumnal equinoxes the sun is situated above this plane, and, consequently, the shadow of P describes the lower curves at A B. During winter, on the contrary, it is the upper curves that are described. It is easily seen that the curves traced by the shadow of the point P are hyperbolas whose convexity is turned toward A B. It therefore appears evident to us that the thread of our sun dial carried a knot or bead whose shadow was followed upon the curves. This shadow showed at every hour of the day the approximate date of the day of observation. The sun dial therefore served as a calendar. But how was the position of the bead found? Here we are obliged to enter into new details. Let us project the figure upon a vertical plane (Fig. 3, No. 1) and designate by H E the summits of the hyperbolas corresponding to the winter and summer solstices. If P be the position of the bead, the angles, P H H¹, P E E¹, will give the height of the sun above the horizon at noon, at the two solstices. Between these angles there should exist an angle of 47°, double the obliquity of the ecliptic, that is to say, the excursion of the sun in declination: now P E E¹-P H H¹ = E P H = 47°.

Let us carry, at H and E, the angles, O H E = H E O = 43° = 90°-47°; the angle at 0° will be equal to 180-86 = 94°. If we trace the circumference having O for a center, and passing through E and H, each point, Q, of such circumference will possess the same property as the angle, H Q E = 47°. The intersection, P, of the circumference with the straight line, N, therefore gives the position of the bead.

Let us return to our instrument. We have traced upon a diagram the distance of the points of attachment of the thread, at the intersection of the planes of projection. We have thus obtained the position of the line, N S. Then, operating as has just been said, we have marked the point, P. Now, accurately measuring all the angles, we have found: N S R = 50°; P H H¹ = 18°; P E E¹ = 65°. The first shows that the instrument has been constructed for a place on the parallel of 50°, and the others show that, at the solstices, the height of the sun was respectively 18° and 65°, decompounded as follows:

18° = polar height of the place -23½°. 65° = " " " " +23½°.

The polar height of the place where the object was to be observed would therefore be 41½°, that is to say, its latitude would be 48½°.

Minor views of construction and measurement and the deformations that the instrument has undergone sufficiently explain the divergence of 1½° between the two results, which comprise between them the latitude of Paris.

After doing all the reasoning that we have just given at length, we have finally found the means by which the hypothetic bead was to be put in place. A little beyond the curves, a very small but perfectly conspicuous dot is engraved--the intersection of two lines of construction that it was doubtless desired to efface, but the scarcely visible trace of which subsists. Upon measuring with the compasses the distance between the insertion of the thread and this dot, we find exactly the distance, N P, of our diagram. Therefore there is no doubt that this dot served as a datum point. The existence of the bead upon the thread and the use of it as a rude calendar therefore appears to be certain.

The compass is to furnish us new indications. After dismounting it--an operation that the quite primitive enchasing of the face plate renders very easy--we took a copy of it, which we measured with care. The arrow forms with the line O C-O R an angle of 90° + 8°. The compass was therefore constructed in view of an eastern declination of 8°.

Now, here is what we know with most certainty as to the magnetic declination of Paris at the epoch in question:

Years. Declinations. 1550. 8° east. 1580. 11.30 1622. 6.30 1634. 4.16

On causing the curve (Fig. 3, No. 3) to pass through the four points thus determined, we find, for 1612, the declination 8½°. This is, with an approximation closer than that of the measurements that can be made upon the small compass, the value that we found. From these data as a whole we draw the two following conclusions: (1) The instrument was constructed at Paris; and (2) the inventor was accurately posted in the science of his time.

Certain easily perceived retouchings, moreover, show that this sun dial is not a copy, but rather an original. We are therefore in an attitude to claim, as we did at the outset, that the constructor of this pleasing object was not only an artist, but a man of science as well.

Let us compare a few dates: In 1612, Galileo and Kepler were still living. Thirty years were yet to lapse before the birth of Newton. Modern astronomy was in its tenderest infancy, and remained the privilege of a few initiated persons.--_C.E. Guillaume, in La Nature._

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[MIND.]

THE UNDYING GERM PLASM AND THE IMMORTAL SOUL.

By Dr. R. VON LENDENFELD.

[The following article appeared originally, last year, in the German scientific monthly, _Humboldt_. It, is reproduced here (by permission)--the English from the hand of Mr. A.E. Shipley--as a specimen of the kind of general speculation to which modern biology is giving rise.--EDITOR.]

To Weismann is due the credit of transforming those vague ideas on the immortality of the germ plasma which have been for some time in the minds of many scientific men, myself among the number, into a clear and sharply-defined theory, against the accuracy of which no doubt can be raised either from the theoretical or from the empirical standpoint. This theory, defined as it is by Weismann, has but recently come before us, and some time must elapse before all the consequences which it entails will be evident. But there is one direction which I have for some time followed, and indeed began to think out long before Weismann's remarkable work showed the importance of this matter. I mean the origin of the conception of the immortal soul.

Before I approach the solution of this problem, it may be advisable to recall in a few words to my readers the theory of the immortality of the germ plasm.

All unicellular beings, such as the protozoa and the simpler algæ, fungi, etc., reproduce themselves by means of simple fission. The mother organism may split into two similar halves, as the amoeba does, or, as is more common in the lowest unicellular plants, it may divide into a great number of small spores. In these processes it often happens that the whole body of the mother, the entire cell, may resolve itself into two or more children; at times, however, a small portion of the mother cell remains unused. This remnant, in the spore-forming unicellular plants represented by the cell wall, is then naturally dead.

From this it follows that these unicellular beings are immortal. The mother cell divides, the daughter cells resulting from the first division repeat the process, the third generation does the same, and so on. At each division the mother cell renews its youth and multiplies, without ever dying.

External circumstances can, of course, at any moment bring about the death of these unicellular organisms, and in reality almost every series of beings which originate from one another in this way is interrupted by death. Some, however, persist. From the first appearance of living organisms on our planet till to-day, several such series--at the very least certainly one--have persisted.

The immortality of unicellular beings is not at any time absolute, but only potential. Weismann has recently directed attention to this point. External occurrences may at any moment cause the death of an individual, and in this way interrupt the immortal series; but in the intimate organization of the living plasma there exist no seeds of death. The plasma is itself immortal and will in fact live forever, provided only external circumstances are favorable.

Death is always said to be inherent in the nature of protoplasm. This is not so. The plasm, as such, is immortal.

But a further complication of great importance affects the reproduction and the rejuvenescence of these unicellular organisms; this is the process of conjugation. Two separate cells, distinct individuals, fuse together. Their protoplasmic bodies not only unite but intermingle, and their nuclei do likewise; from two individuals one results. A single cell is thus produced, and this divides. As a rule this cell seems stronger than the single individual before the union. The offspring of a double individual, originated in this way, increase for some time parthenogenetically by simple fission without conjugation, until at length a second conjugation takes place among them. I cannot consider further the origin of this universally important process of conjugation. I will only suggest that a kind of conjugation may have existed from the very beginning and may have been determined by the original method of reproduction, if such existed.

At any rate conjugation has been observed in very many plants and animals, and is possibly universally present in the living world.

Conjugation does not affect the theory of immortality. The double individual produced from the fusion of two individuals, which divides and lives on in its descendants, contains the substance of both. The conjugating cells have in no way died during the process of conjugation; they have only united.

If we examine a little more closely the history of such a "family" of unicellular beings from one period of conjugation to the next, we see that a great number of single individuals, that is, single cells, have proceeded from the double individual formed by conjugation. These may all continue to increase by splitting in two, and then the family tree is composed of dichotomously branching lines; or they may resolve themselves into numerous spores, and then the family tree exhibits a number of branches springing from the same point.

The majority of these branches end blindly with the death, caused by external circumstances, of that individual which corresponds with the branch. Only a few persist till the next period of conjugation, and then unite with other individuals and afford the opportunity for giving rise to a new family tree.

All the single individuals of such a genealogical table belong to one another, even though they be isolated. Among certain infusoria and other protista, they do, in fact, remain together and build up branching colonies. At the end of each branch is situated an infusorian (vorticella), and the whole colony represents in itself the genealogical family tree.

In the beginning, there existed no other animal organisms than these aggregations of similar unicellular beings, all of which reproduced themselves. Later on, division of labor made its appearance among the individuals of the animal colony, and it increased their dependence upon one another, so that their individuality was to a great extent lost, and they were no longer able to live independently of one another.

By the development of this process, multicellular metazoa arose from the colonies of similar protozoa, and at length culminated in the higher animals and man.

If we examine the human body, its origin and end, in the light of these facts, we shall see that a comparison between the simple immortal protozoa and man leads us to the result that man himself, or at least a part of him and that the most important, is immortal.

When we turn to the starting point of human development, we find an egg cell and a spermatozoon, which unite and whose nuclei intermingle. Thus a new cell is produced. This process is similar to the conjugation of two unicellular beings, such as two acinetiform infusoria, one of which, the female ([Symbol: Female]), is larger than the other, the male ([Symbol: Male]). This difference of size in the conjugating cell is, however, without importance.

From this double cell produced by conjugation many generations of cells arise by continual cell division in divergent series. Among the infusoria these are all immortal, but many of them are destroyed, and only a few persist till conjugation again takes place. The same is the case with man. Numerous series of cell families arise, which are all immortal: of these but few--strictly speaking, only one--live till the next period of conjugation and then give the impulse which results in the formation of a new diverging series of cells. The difference between man and the infusorian is only that in the former the cells which originate from the double cell (the fertilized ovum) remain together and become differentiated one from another, while in the latter the cells are usually scattered but remain alike in appearance, etc.