VOL. I.

ORIGINAL ARTICLES.

STUDY OF IMMUNITY.

BY M. METCHNIKOFF.

IV. PREVENTIVE PROPERTY OF THE SERUM OF VACCINATED RABBITS.

WE have already shown that the serum of vaccinated rabbits protects rabbits against hog cholera. This result is very constant, and may be obtained not only by injecting serum at the same point as the virulent blood, but also by introducing it at points very remote from the place of inoculation. The rabbits receiving under the skin a quantity of most virulent blood sufficient to kill witness rabbits, and likewise the serum of vaccinated rabbits, manifest only a local suppuration, and surely recover. The serum injected into the veins preserves equally rabbits to which a mortal dose of virus has been inoculated under the skin.

The serum may be injected at the same time or before the introduction of the virus. A rabbit which received thus in the auricular vein, 4, 5, c. c. of serum of a vaccinated rabbit, resisted perfectly an inoculation of 0,33 c. c. of virulent blood (a mortal dose for a witness), injected in the subcutaneous tissue.

While the serum of vaccinated rabbits is a very efficacious preventive against subcutaneous inoculation, it only retards death if the virus be introduced into the veins. In an experiment in which the virulent blood was injected into the auricular vein, the rabbit which had received 3, 5 c. c. of vaccinal serum, died in forty-two hours, while the witness which had not been treated with the serum died in five hours and twenty minutes. The injection of a stronger

NO. 11.

lose of serum would, perhaps, have acted in a more efficacious manner.

The minimum dose of serum necessary to prevent death (after the subcutaneous injection of virus) is 0,5 c. c. In an experiment in which I used only O,25 c. c., death was not prevented, but it occurred five days after that of the witness.

All the rabbits vaccinated against hog cholera furnished vaccinal serum. The serum obtained from blood withdrawn a short time (five days) after the proof inoculation, is itself as active as that withdrawn at more advanced periods.

The vaccinating property of the serum depends more on the quantity of toxines injected into the vaccinated rabbits than the really refractory state of the latter. I deduct this conclusion from a few observations which I have been able to make in the course of my researches. I have seen rabbits vaccinated with doses more than sufficient (4 c. c. of toxic blood), which had resisted the proof inoculation, die finally with evident signs of general infection of the microbe of hog cholera, and still their serum, withdrawn a few days before death, was so active that 0,5 c. c. sufficed to preserve a rabbit against mortal infection with virulent blood injected subcutaneously.

On the other hand, rabbits cured of hog cholera by treatment with serum of vaccinated rabbits, furnish themselves a serum which does not interfere with the mortal malady in other rabbits. Notwithstanding this, the cured rabbits above mentioned have acquired immunity against other virulent virus.

The efficacy of the serum of vaccinated rabbits not totally refractory against hog cholera, is evidently due to previous injections of sufficient quantities of toxic blood.

The attempts at treatment with preventive serum of rabbits inoculated previ

ously with virus have not been numerous. They have not given me, as yet, any positive results, probably because of the rapidity with which hog cholera evolves in rabbits.

In multiplying these researches, we might perhaps obtain better success, but the study of this problem did not enter into the plan of this work; it has been reserved for later efforts.

The experiments for the prevention of the malady by means of serum sufficed, of themselves, to demonstrate the efficacy of this liquid when coming from the organism of vaccinated rabbits.

But as the serum is a very complicated mixture, which cannot be identified with the blood plasma, it would be interesting to have a more precise idea of the preventive role of each of its constituting parts. Unfortunately, it is impossible to separate the diverse elements of the blood of rabbits, so the problem cannot be solved under the present scientific methods.

We cannot, then, know whether the preventive substances of the serum come from the plasma or the cellular elements. Concerning the latter, I will mention that the blood of vaccinated rabbits is richer in leucocytes than the normal blood.

With the object of contributing to the enlightening of the problem, I have made a few experiments with the liquid of oedema provoked by stopping the circulation. At the base of the ear of three vaccinated rabbits (the serum of which had plainly manifested its preventive properties) a rubber ring was placed. The following day the ear was found hanging, swelled by the oedema. The oedematous liquid was easily gathered in sterilized pipettes. It was absolutely transparent, colorless, and contained only an insufficient number of leucocytes. By the same processes, I have been able to extract œdematous liquid from three witness rabbits not vaccinated.

kinds of oedematous liquid is, consequently, very striking, while in the serum it is almost null.

Inoculated in the veins of the eye, or under the skin of rabbits, the cultures in the liquid of the oedema of the vaccinated appeared just as active as in those of control. The slight differences observed had no value, and are explained by the variations in weight and other individual characteristics of inoculated rabbits.

These experiments demonstrate that there is a very considerable difference between the influence of the liquid of the oedema and the complete serum of vaccinated rabbits. These prove, besides, that the variations in the form and growth of the bacteria (strepto-bacilli instead of diplo-bacilli) have no relation to the virulence.

The striking difference between the serum obtained out of the animal organism and the liquid of the cedema drawn directly from it, indicates to what point it would be imprudent to conclude, from the particularities of the serum, the phenomena to be due, which occur in the vaccinated organism. It is necessary, therefore, to study the properties of the latter.

This same postulate arises from the consideration that the preventive activity of the serum cannot be explained by the bactericide property, anti-toxic property, nor by the attenuative power of this humor. If the preventive serum does not act on the bacteria and its toxines, it is because it must exert its influence on the organism subjected to the treatment. (To be continued.)

A RENAL CALCULUS OF UNUSUAL SIZENEPHRECTOMY-RECOVERY.

BY J. H. KELLOGG, M. D. Superintendent Sanitarium, Battle Creek, Mich.

A PATIENT, Mrs. W., aged — years, was brought to me for examination, September

had suffered for a long time from pain in the right side, and some time previously the doctor had discovered a hard mass, which upon investigation proved to be an enlarged and prolapsed kidney. The mass was so large that it filled almost the entire right side, reaching from the lower ribs to considerably below the crest of the ilium, and extended inward nearly to the

- median line. The patient suffered so much pain, and was evidently losing ground so rapidly, through the immense quantities of pus discharged with the urine daily, that I thought it best to advise the removal of the diseased organ, and after proper preparation of the patient, proceeded to operate.

My first intention was to operate by the abdominal method, on account of the great size of the mass, but at the last moment I concluded to undertake the operation by the lumbar method, fearing that some condition might be encountered which would render nephrectomy impossible or imprudent, so that the operation might be terminated as a nephrotomy, recalling a remark made by Mr. Lawson Tait, in conversation with the writer when a student assistant with him, in which the operation of nephrectomy was totally condemned, nephrotomy being considered by Mr. Tait the only justifiable operation upon the kidney. Mr. Tait's argument was, that any condition of the kidney likely to be benefited by an operation requires nothing more than nephrotomy, the cases in which nephrectomy would be of any service being in his opinion hopeless, even with a radical operation.

The operation was begun by a vertical incision reaching from the last rib to the crest of the ilium. When the kidney was reached, it was found to be closely adherent to its capsule, as the result of repeated inflammatory attacks which had also consolidated the fat lying outside of the capsule, making it even more difficult to separate the capsule from the adjacent tissues than to break up the adhesions between the kidney and the capsule. It was evident that a large opening would be required for the removal of the mass, and a transverse incision four inches in length, starting from the middle of the first incision, and running toward the linea alba, was accordingly made. This extension of the incision enabled me to introduce the whole hand, and by patient effort, the adhesion between the kidney and its capsule was finally completely broken up. It was, however, found impossible to extricate the enormous mass, although the opening was made as large as possible without entering the peritoneal cavity, by further extension of the transverse incision. I accordingly laid bare and amputated the anterior two thirds of

the last rib, and by a considerable effort was then able to pull and push the kidney out of its bed. The central portion of the mass presented a stony hardness, which, taken together with a nodular appearance and feeling of the organ, suggested the probability of a malignant disease. organ also presented several cyst-like masses, one of which was the size of a large orange.

The

As

After ligating the pedicle, excluding the ureter and inclosing the vessels in a separate ligature, I proceeded to amputate the mass, when I at once discovered, from the gritty sensation imparted to my knife, that the central hardness was due to an immense renal calculus which filled the whole interior of the organ. soon as the pelvis and the kidney were laid open, a great quantity of mingled pus, mucus, and urine which had been dammed back by the calculus, producing the cystic condition before referred to, rushed out. Precaution had been taken to protect the wound, as far as possible, from infection from this source, and the tissues exposed were thoroughly disinfected; the operation was quickly terminated, two drainage tubes being introduced into the deeper parts of the wound, which was closed by deep sutures, which, when tied, obliterated almost entirely the cavity left by the removal of the kidney. The upper portion of the ureter, which was enormously dilated and thickened, was stitched to the skin. The ligatures were left long so as to facilitate removal, absolute aseptic management of the wound being evidently impossible. Considerable hemorrhage occurred during the operation, as the tissues lying about the kidney were exceedingly vascular. This was well controlled, however, by stuffing the wound from time to time with sterilized gauze and by application of sponges wet in hot

water.

The calculus was found to weigh 137 grams, the largest of the kind removed during life of which I have found any record. A photo-reproduction of the calculus, natural size, is presented as the frontispiece of this number.

The patient made a rapid and excellent recovery. The temperature subsequent to the operation, did not at any time exceed 101.4°. Only the very slightest suppuration occurred, so that the tubes were removed in a few days. On the

tenth day all the sutures were removed. Within a few days subsequent to the operation, the condition of the patient was found to be decidedly better than before the operation. The pus, which before the operation had been so great in quantity as to render the urine very thick and its filtration very slow, had disappeared almost entirely. Before the operation, the quantity of urine passed in twenty-four hours was 850 c. C.; the specific gravity, 1018; urea, 18.7 grams; total solids, 30.6 grams. The pus was so great as apparently to constitute fully one half of the total amount of liquid; and boiling, after the addition of nitric acid, showed a quantity of albumen 1-32nd of the volume of the urine tested.

The toxicity of the urine, as determined by the method of Bouchard, which consists of an injection of the urine into the veins of a rabbit in quantities sufficient to produce death, was as follows: The amount required to kill a rabbit weighing 1.4 kilos, 40 c. c., making a urotoxie, or the amount required to kill one kilogram of rabbit, 28.6 c. c.; the total number of urotoxies produced in twenty-four hours, or the possible amount of living being killed by the urine of twenty-four hours, 29.7 kilos; the urotoxic coefficient, or possible amount of living being killed by the urine produced by each kilogram of patient in twenty-four hours, .6. The rabbit died in two minutes from the beginning of the injection, with slight spasm, the pupil being first contracted, then dilated; the temperature rose .4 of one degree C. In three days after the operation, the amount of urine was found to be 900 c. C. The reaction, formerly extremely alkaline, had become normally acid, 10 c. c. of the urine requiring 1.5 c. c. of the decinormal solution of sodium hydrate to neutralize it. The specific gravity was 1030; the urea, 48.6 grams; there was a bare trace of albumen, and only a few pus corpuscles to be found in each field. One half minute after the beginning of the injection, the rabbit's pupils began to contract, and a powerful tetanic spasm occurred, which continued until death, one minute after the injection began. The pupils were extremely contracted, and there was pronounced exophthalmus, but no change in tempera

ture.

The toxicity was found to be as follows: Amount required to kill a rabbit, the

weight of which was 1.8 kilos, 16 c.c.; urotoxie, 8.6; number of daily urotoxies, 104.6; the urotoxic coefficient, 2.113. The amount of urea produced by the one kidney subsequent to the operation was more than two and one half times that produced before the operation. The amount of total solids was more than double, and the toxicity was two and one half times as great, being nearly five times greater than normal, indicating an abnormal increase of toxic matters in the system subsequent to the operation, perhaps in part the result of absorption from the extensive wound, although sepsis in the wound was almost entirely absent.

October 2, three weeks after the operation, an examination of the urine gave the following results: Quantity for 24 hours, 1421 c.c.; specific gravity, 1016; urea, 21.3; total solids, 55.47 grams.

A very slight sediment, consisting of urates, phosphates, and oxulates ; no pus ; no albumen; reaction natural.

The

These observations are of interest, as showing the ability of a kidney to assume double duty at once, when called upon to do so, and even to do an amount of work considerably greater than that ordinarily performed by two sound kidneys. patient's suffering the night following the operation, was so slight that considerable sleep was obtained. She has already recovered from the operation, and, with the exception of being somewhat weak from confinement in bed, is in every way in a better physical condition than before the operation was performed.

BEFORE presenting a series of cases illustrative of the different types and varieties of stomach disorders as relates to the disturbance of the normal chemical processes of digestion, it may be well to recall briefly the significance of the different quantities which furnish the basis of classification. Each of the quantities represented by the symbols (A), (A'), (a), (T), (H), and (C), teaches an

1 The matter contained in this article was presented at the Cincinnati meeting in a paper by the author, entitled "Methods of Precision in the Investigation of the Disorders fo Digestion, or The New Chemistry of the Stomach."

important fact in relation to the work done by the stomach.

This fact is clearly shown by one or two remarkable cases, the details of which will be given later in this paper, in which the value of a is ∞, being represented by a fraction with a whole number for a numerator, and zero for a denominator,

C

value, .86. A higher figure represents the presence of abnormal acids resulting from fermentation. A lower value shows the presence in the quantity C of neutral chloro-organic combinations having a resemblance to normal digestive products, but without nutritive value, and which contribute nothing to the acidity of the stomach fluid. Both of these facts are of great importance, and as the information conveyed by them can be obtained in no other way, the value of a as a means of determining the quality of the chemical work done by the stomach will be readily appreciated. When below the normal figure, it indicates with certainty that the value C is depreciated by neutral chloro-organic compounds; but the amount of this depreciation is not so clearly indicated by the lowered value. of a as is the amount of acid fermentation by its increased value, since the neutral compounds in C may be, to a greater or less extent, neutralized by the products of acid fermentation. Thus, while we are able to say that acid fermentation is present whenever we find a above the normal figure, we cannot with equal certainty say that acid fermentation is not present when a is less than the normal figure.

x

It

Here x represents the amount of acidity due to the products of acid fermentation. It is evident that C might in a given case possess such a value, although wholly composed of neutral compounds, as to mask completely the value. x, thus hiding the presence of the abnormal acids. The amount of acidity due to the products of fermentation which can be hidden in this way, is, however, comparatively so small that this fact does not materially lessen the value of a as an index to the quality of the chemical work done in the digestive process, and it may properly be regarded as the coefficient of digestive work. should be remembered that a represents, not a definite quantity, but simply the proportion which exists on the one hand between the acidity normally due to the chloro-organic compounds, or C, and the increased acidity due to the presence of the products of the acid fermentation, or the diminished acidity due to the presence of neutral compounds. in C. When a is found to be zero, as we have observed in a number of instances, the indication is positive both that acid fermentation is wholly absent, and that C is wholly composed of neutral and worthless. compounds. a becomes when C is o, and when A exceeds H, the result obtained by subtracting H from A in this case representing exactly the amount of acidity due to acid fermentation. The significance of a when found to be o or ∞, is readily shown by the following formulæ :

Recalling the formula A = H+C+x, in which a represents the products of acid fermentation, and the formula derived C x C

from the foregoing C

+ it