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The Etiology of Foot-and-Mouth Disease
ABSTRACTS AND REPORTS.
minutes at 68° c.; the rabbit died two hours and forty minutes after the inoculation. Rabbit NO.3 received the same dose of the preceding mixture heated for ten minutes in a sealed tube at 68° C. Death resulted four hours after the inoculation. Rabbit NO.4 received I mIlligram me of snake poison mixed with 3 cubic centimetres of normal serum of the rabbit; the mixture as before was heated for ten minutes at 68° C. in a sealed tube, Death took place three hours and thirty minutes after the inoculation. These experiments showed that heating to 68°, which deprives the serum of its antitoxic power, leaves the snake poison intact, and that the toxic power of the latter is not in the least diminished in spite of the previous mixture with the antitoxin. The heat has acted on the mixture as it would have done on the serum and on the snake poison taken separately. One must conclude from this that the snake poison was neither modified nor destroyed by the serum, and that it had not formed any combination of the two substances, or that if there was such a combination it was very unstable. Hence one may suppose that if the serum is preventive and therapeutic, and th3t if when injected with the snake poison it prevents that from acting, it is because, as M. Roux has explained, it in some way lin mediately renders the cells of the organism insensitive with regard to the snake poison. The mechanism of this action has hitherto escaped our observation, but the laws of phagocytosis, so brilliantly studied by M. Metschnikoff, permit us to understand that the functions discharged by leucocytes with regard to bacteria and foreign bodies of the most various kind, may be exercised also toward various poisons.
THE ETIOLOGY OF FOOT-AND-MOUTH DISEASE. and Fiorentini assert that the agent which is the cause of foot-andmouth disease does not belong to the bacteria. In certain stages of the disease they found in the exudate of the vesicles, in the i"olated epithelial cells, in the corium connected with the vesicles, and abo III the circulating blood, small corpuscles which are not constituents of the normal animal body, nor morbid products derived from these. In fresh material these corpuscles present themselves as hyaline spheres with a diameter of from 1- to 4 micromiliimetres and rather strongly refractile; sometimes the spheres contain in their interior one or more refractile granules, or are provided with a relatively large clear nucleus which is less refractIle than the protoplasm. Sometimes 'hyaline spheres of from -l- to 5 micro-millimetres in diameter contain several large hyaline granules; these corpuscles frequently show pseudopodia, and at a high temperature they may even exhibit ama;boid movements. The corpuscles retain their vitality external to the animal body when a little glycerine is added to the exudate taken from the vesicles and access of air is excluded. From all these facts the authors conclude that these corpuscles are the canse of foot-and-mouth disease. As the result of his investigations, a German physician, Dr Bela, has also arrived at the conclusion that foot-andmouth disease is not caused by a vegetable parasite but by protozoa.-Berliner Tltier. TVocher. PIAN!
AN ABNORMAL VARIETY OF THE BACILLUS OF BLACK-QUARTER. the typical form of the bacillus of black-quarter, two other forms, differing from the ordinary bacillus in their morphological characters and their
,BESIDES
minutes at 68° c.; the rabbit died two hours and forty minutes after the inoculation. Rabbit NO.3 received the same dose of the preceding mixture heated for ten minutes in a sealed tube at 68° C. Death resulted four hours after the inoculation. Rabbit NO.4 received I mIlligram me of snake poison mixed with 3 cubic centimetres of normal serum of the rabbit; the mixture as before was heated for ten minutes at 68° C. in a sealed tube, Death took place three hours and thirty minutes after the inoculation. These experiments showed that heating to 68°, which deprives the serum of its antitoxic power, leaves the snake poison intact, and that the toxic power of the latter is not in the least diminished in spite of the previous mixture with the antitoxin. The heat has acted on the mixture as it would have done on the serum and on the snake poison taken separately. One must conclude from this that the snake poison was neither modified nor destroyed by the serum, and that it had not formed any combination of the two substances, or that if there was such a combination it was very unstable. Hence one may suppose that if the serum is preventive and therapeutic, and th3t if when injected with the snake poison it prevents that from acting, it is because, as M. Roux has explained, it in some way lin mediately renders the cells of the organism insensitive with regard to the snake poison. The mechanism of this action has hitherto escaped our observation, but the laws of phagocytosis, so brilliantly studied by M. Metschnikoff, permit us to understand that the functions discharged by leucocytes with regard to bacteria and foreign bodies of the most various kind, may be exercised also toward various poisons.
THE ETIOLOGY OF FOOT-AND-MOUTH DISEASE. and Fiorentini assert that the agent which is the cause of foot-andmouth disease does not belong to the bacteria. In certain stages of the disease they found in the exudate of the vesicles, in the i"olated epithelial cells, in the corium connected with the vesicles, and abo III the circulating blood, small corpuscles which are not constituents of the normal animal body, nor morbid products derived from these. In fresh material these corpuscles present themselves as hyaline spheres with a diameter of from 1- to 4 micromiliimetres and rather strongly refractile; sometimes the spheres contain in their interior one or more refractile granules, or are provided with a relatively large clear nucleus which is less refractIle than the protoplasm. Sometimes 'hyaline spheres of from -l- to 5 micro-millimetres in diameter contain several large hyaline granules; these corpuscles frequently show pseudopodia, and at a high temperature they may even exhibit ama;boid movements. The corpuscles retain their vitality external to the animal body when a little glycerine is added to the exudate taken from the vesicles and access of air is excluded. From all these facts the authors conclude that these corpuscles are the canse of foot-and-mouth disease. As the result of his investigations, a German physician, Dr Bela, has also arrived at the conclusion that foot-andmouth disease is not caused by a vegetable parasite but by protozoa.-Berliner Tltier. TVocher. PIAN!
AN ABNORMAL VARIETY OF THE BACILLUS OF BLACK-QUARTER. the typical form of the bacillus of black-quarter, two other forms, differing from the ordinary bacillus in their morphological characters and their
,BESIDES