VETERINARY SCIENCE AND PRACTICE. 93 



ducted a number of experiments for the purpose of determining the action of rat 

 serum upon the anthrax bacilkis. 8mall quantities of the first and second vaccine 

 and of virulent cultures were inoculated in 20 mixtures of bouillon and rat serum, 

 which were arranged in a series, beginning with 19 droi)s f)f bouillon to one drop of 

 rat serum, and ending with the i)ure serum. The results of these experiments indi- 

 cated that the action of the tliastase contained in the rat serum is more noticeable in 

 distilled than in physiological water, and more so in the latter medium than in 

 bouillon. The first vaccine was more sensitive to the action of diastase than the sec- 

 ond vaccine, and the latter more sensitive than the virus. V^ery small quantities of 

 serum favored the active growth of the bacillus. From these experiments the author 

 concludes that rat serum does not contain a true Ijacteriolytic diasta.se, but only a sub- 

 stance analogous to antiseptics, which paralyzes the functions of assimilation and 

 growth of the bacillus, while it favors the secretion and digestive action of a diasta.se 

 which is secreted by the anthrax bacillus. The bacillus protects itself against the 

 action of rat serimi by the formation of a mucila;^inous sheath. The immunization 

 of the bacillus against this substance does not render it more resistant to autodiges- 

 tion, but simply permits it to produce new cultures. Rat serum deprived of its anti- 

 septic constituent is a good culture medium for the anthrax bacillus. 



By comparing the results obtained in these experiments with those indicated by 

 experiments with solutions of arsenic, the author concludes that the digestion of 

 the bacillus in rat serum is a phenomenon of similar nature to that of its digestion in 

 suita])le solutions of arsenic. The antipathetic substance formed by the bacillus has 

 no direct action upon the diastase, and does not arrest the development of patho- 

 genic symptoms. 



Experimental studies on blackleg; immunization by serum, E. Leclainche 

 and H. \'allee (A'cr. V<t. TuiUouac, „>J {J MO), Xu. 1^, pp. 7-^.5-756).— The authors' 

 experiments were arranged in 2 series. In the first series a goat which had been 

 inununized by a virulent intravenous injection, received during a period of 6 months 

 subi;utaneous inoculations of muscle tissue from infected guinea pigs. The first 

 inoculations produced rather serious local lesions. Later inoculations, however, 

 caused no reaction. The serum of the goat acquired immunizing properties rather 

 slowly. After 3 inoculations, at intervals of 10 days, with 5, 10, and 15 cc. of filtered 

 material from infected guinea pigs, a serum was obtained which, in doses of from 1 

 to 5 cc, protected guinea pigs against inoculations of ^ cc. of virulent material. In 

 the second series of experiments pure cultures of Bacterium chaund were used. • Two 

 horses were used in these experiments, having been immunized by intravenous 

 injections of pure cultures. They were subsequently treated by intravenous injec- 

 tions of virulent serous fluid in one case and of pure culture in bouillon in the other. 



The authors found that a sulx'utaneous injection of serum produces an immuniza- 

 tion in organisms thus treated which i)ermits them to endure rejjcated inoculations 

 with the virulent material. Both the horses and the goat were rapidly brought to a 

 condition where they furnished immunizing serum. A fatal dose of virus mixed 

 with a small quantity of immunizing serum becomes neutralized. The simultaneous 

 injection at different parts of the body of virus and serum does not produce any 

 increased resisting power in the guinea pig. It was found that an indifferent serum 

 obtained from horses or cattle would not bring about agglutination, even in the pro- 

 portion of 1 to 12, while the serum of an immunized horse produced immediate 

 agglutination in the proportions of from 1 to 30 to 1 to 3,000. The authors conclude 

 that serum is endowed with preventive iinjperties and that it confers merely a tem- 

 porary immunity. Serum and virus when mixed neutralize each other without 

 conferring a permanent inmmnity. Fnnn a practical standpoint the authors l>elieve 

 that serum therapy must be restricted in use, and that vaccination by means of pure 

 virus is the method to be chosen, as being more simple and certain. 



