was resorted to. Immunity against snake-venom, or rather a ' resistance' to it, was produced in animals, either by the means of the same chemicals or by repeated injections of very small doses of the snake-venom, or by introducing it in small doses into food, until it was found much safer to confer immunity by means of injections of attenuated snake-venom. And after that, the serum of animals thus rendered immune was experimented upon as a cure for other animals into whose blood the snake-poison had been introduced. Finally, it was tried upon men who had been bitten by snakes.

Already in 1888 it had become known, through the remarkable researches of Kaufmann,31 that an animal can be rendered capable of resisting snake-poison if very small doses of the same be repeatedly injected in its tissues. Mr. Sewall and Dr. Kanthack fully confirmed and extended these conclusions by independent research.32 But, valuable as this first step was for further investigations, it had no immediate practical application; it would, of course, be impossible to vaccinate and re-vaccinate every man and beast in a country infested with snakes.

Consequently, the French doctor Calmette, who was in 1892 at Saigon, endeavoured to discover such chemicals as could be used as counter-poisons in the human organism. The most interesting was that he really obtained some partial success with the above-mentioned chemicals; ; 33 but the numerous failures of this method soon induced him, when he came to the Paris Pasteur Institute, to devote his attention to a more effective method—namely, the serum treatment. Two other French bacteriologists, C. Physalix and G. Bertrand, worked in the same direction; and on the same day (February 10, 1894), both Physalix and Bertrand, and Calmette, read papers at the French Société de Biologie, to announce that they had obtained satisfactory and encouraging results by using the serum of previously immunised animals as a cure for snake-poison.

34

Since that time, Dr. Calmette has fully worked out his method.35

31 Mémoires de l'Académie de Médecine, 1889 (this memoir was crowned by the Academy), quoted by Chauveau, in Comptes Rendus, 1894, t. 118, p. 936. Also Revue Scientifique, t. xlv. p. 180.

32 See Dr. Canthack's very lucid and suggestive article on the whole subject, 'A Rational Cure for Snake-bites,' in Nature, 24th of October, 1895, vol. lii. p. 621, where the literature is mentioned.

33 His successes and failures were mentioned in this Review, December 1894.

34 A contest of priority having arisen on this occasion, the correspondence relative to it will be found in the Comptes Rendus of the French Academy, 1894, t. 118, pp. 935, 1004, and 1071.

35 His memoirs were published in the Annales de l'Institut Pasteur, May 1894, p. 275; April 1895, p. 225; and March 1897, p. 214. Also in Comptes Rendus, 27th of March, 30th of April, 1894 (t. 118, pp. 720 and 1004); 1895, t. 120, and 1897. The substance of his work was communicated by Dr. Roux to the International Congress of Medicine and Hygiene, at Buda-Pesth, in September 1894, and Roux's address was published in the Annales de l'Institut Pasteur, October 1894, and reproduced in many periodicals. The memoirs of Physalix and Bertrand are also in the

Already in 1894 he had convinced himself of the superiority of the serum treatment; 36 but, as serum cannot be always kept in readiness in every village, and as some cures had been effected by means of chemicals, he recommended this last method in case of need.

Next year, i.e. in May 1895, Calmette published the quite positive results which he had obtained for the serum treatment. Small doses of attenuated cobra poison (heated to about 212° Fahr.) were repeatedly injected into rabbits; and after some time the little creatures were rendered so perfectly immune that a dose of pure cobra-poison sufficient to kill eighty rabbits could be introduced into the blood of one of them without any danger to its health. The serum of the blood of such rabbits, as was fully proved by many experiments, was endowed with a powerful curative property for other animals. Rabbits which were dying from inoculations of cobra poison recovered in a few hours when the curative serum was injected in their tissues. In September 1894, Calmette began also to immunise donkeys, and it appeared that their serum was also endowed with such curative properties for snake poison that 'cure was the rule.' The serum treatment for snake-bites was thus found. There remained only to prepare large quantities of the precious liquid, that it might be distributed in the colonies, and wait till its properties should be tested on men bitten by snakes. The Pasteur Institute at Lille undertook this work.

Two months after the appearance of the just-mentioned paper of Calmette, Dr. Fraser, who seems to have worked in complete ignorance of Calmette's previous two years' work,37 made a communication before the Edinburgh Royal Society on the same subject. He also had immunised rabbits by injections of very small doses of snakepoison, or by giving it in the animals' food; he also had experimented, upon animals, on the preventive and the curative properties of the serum of these rabbits, and he began to immunise a horse, but could not continue, having no snake-venom; and he also came to the fact that the serum of an animal vaccinated against the cobra-poison, had curative properties against the venoms of several other species.38

In July last, Dr. Calmette was invited to London, to repeat his experiments upon animals before a Special Commission nominated by the Royal Colleges of Physicians and Surgeons. The results of these Comptes Rendus, 5th and 12th of February, 1894 (t. 118, pp. 288 and 356). Since that time these two explorers have carried on most interesting researches, perhaps not yet fully appreciated, into the anti-toxines which are produced in the organism of vipers and other reptiles, in order to counteract the poisons secreted by their own cells (Comptes Rendus, t. 121, p. 745).

* Annales de l'Institut Pasteur, May 1894, pp. 284–289.

"See the correspondence exchanged on this subject between Professor E. Ray Lankester and Dr. Fraser, in Nature, vol. liii. pp. 129, 150, and 175, 12th, 19th and 26th of December, 1895.

38 Communication made before the Edinburgh Royal Society, on the 3rd of June, 1895, in British Medical Journal, 15th of June, 1895, pp. 1309-12.

experiments were very impressive. They proved,' the Commission wrote, 'to evidence that the serum treatment for snake-bites, each time that it can be employed without delay after the bite, must considerably diminish the mortality.' 39 Its use for both men and animals was warmly recommended.

These previsions were soon fully confirmed, and we have now, in the last number of the Annales of the Pasteur Institute, full details about the cases which were treated with Calmette's serum (prepared at the Pasteur Institute of Lille) in India and elsewhere, only those cases being mentioned in which the species of the biting snake was known. The results are simply striking. Thus, last year, in January, a lot of living cobras (Naja tripudians)—all hungry, of course, which renders their bites still worse-was received at Saigon, and the box was opened in the laboratory. One of the young aids was bitten by one of these terrible snakes in the hand. The hand and the forearm were at once paralysed, and serum could be injected only one hour after the bite; nevertheless, the young man, after passing a very bad evening, recovered during the night. Two days later he resumed his work in the laboratory.

He

In India, at Nowgong, Captain Jay Gould saved a soldier of the 5th Cavalry regiment who had been bitten by a krait (Bungarus cæruleus) which was killed on the spot. The captain at once made a ligature to prevent the poison from spreading, and rode full speed to obtain the serum. The injection was made, and the soldier was saved. Another soldier, in Guinea, owes his life to the same treatment. was bitten by a black Naja, which he killed himself, and was in a very bad condition when Dr. Maclaud injected the serum: he recovered in a couple of days. A third soldier was cured in the same way by Dr. Gries in Martinique. He and his comrade had caught a Bothrops lanceolatus, and they were going to put its neck into a split stick, when one of the two comrades was bitten by the snake.

The most striking cure was made at Cairo, in October last. A girl, thirteen years old, was bitten in the forearm by a snake at Gizeh while she was picking cotton. It was then between three and four in the afternoon, and only at seven she was brought to the hospital in a desperate condition. When the doctors-Professors Keatinge and Dr. Ruffer-examined her, at half-past seven, she was in a state of full collapse. The pulse was hardly felt at all, the pupils of the eyes showed no reaction to light. Twenty cubic centimetres of serum were injected under the skin in the abdominal region. At eleven an amelioration in the state of the poor girl became evident, and another ten cubic centimetres of serum were injected. All next day the girl remained drowsy, but recovery set in, and she was saved.

39 I translate from the French text, Annales de l'Institut Pasteur, 25th of March, 1897, p. 214. Also Nature, 20th of August, 1896, vol. liv. p. 380.

Dr. Jornes, of the Cairo Zoological Museum, has not the slightest doubt about the snake having been a Naja haje.

In twelve cases, of which I mention the most characteristic only, the treatment was attended with full success. Besides, many other cases were treated, always with success, but they are not mentioned because the snakes were not caught, and there may be some doubt as to the snakes having not been venomous-which is a justifiable but not absolutely necessary caution, because non-venomous snakes, as is only too well known to snake charmers, do not bite. The best of it is, however, that the preparation maintains its curative properties for a relatively long time. Serum which was sent to India, and was returned one year later from Agra to France, was as effective as if it were freshly prepared.

Of course, further experiments will be required before medical opinion is definitely settled upon the serumtherapy for snake-bites. But these first results are decisive enough, and they are sure to give serumtherapy a new impulse, the more so as science seems to be on the eve of another important discovery—namely, the means of obtaining curative serum in a quite novel and simpler way. But of these new researches, made in Russia by Dr. Smirnoff, as well as of the results obtained by Dr. Haffkine with cholera vaccinations, and Koch's new tuberculin, more will have to be said on some other occasion. They belong to a different domain, in which new vistas are opened upon the very substance of bacteria poisons, as well as upon the structure of blood.

P. KROPOTKIN.

THE GROWTH OF CASTE IN THE

UNITED STATES

I REMEMBER hearing in Boston, from one who was alive at the time, a queer story of Mr. Thackeray's visit to that town. Mr. Thackeray brought from England a letter of introduction to an important gentleman of Beacon Street. By him he was most hospitably entertained, and passed from dinner party to dinner party. But Thackeray's interest in the capital of New England did not end with Beacon Street dinner parties. He had heard something of the eminent men of the town, and at that moment happened to be particularly interested in Theodore Parker. He wished very much to hear this celebrated Unitarian preacher. He mentioned this desire to his host. The Beacon Street gentleman seemed much surprised, but, without abating any of his outward courtesy, and making some valid excuse, took him to King's Chapel on Sunday morning instead of to Music Hall, where Parker preached. At King's Chapel, the Beacon Street gentleman said, people of the best society might always be found. Thackeray, it is needless to say, was a mild-mannered man, not fond of a struggle to free himself from his entertainer's clutches. He saw that it was impossible for him to get on Sunday to Music Hall. But during the week he heard that Parker was to deliver a discourse at the funeral of a rich and public-spirited merchant. Thackeray went alone to the funeral, and was greatly interested and thrilled by the address. He also saw many people who looked as if they were more interesting than any he had seen at the Beacon Street dinner parties. He went home that afternoon to dinner, and found that his host had invited to meet him several gentlemen of the best society, most of whom were bores. Thackeray could not help telling about Parker and the funeral, and confessing how much he had been impressed by the preacher and the people. His host was visibly distressed, and presently managed to whisper in his ear, 'I beg of you, Mr. Thackeray, to remember that Mr. Parker does not belong to our best society'! This was more than the Englishman could stand, and he replied, loud enough to be heard by at least one at the table: Upon my word, I begin to wish I hadn't got into good society when I came to Boston!' The story is amusing, perhaps, and expresses the general im

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