INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 1017 



it multiplies tliere by division only, not by spores. Some animals are 

 more readily affected by it than others (e. g. the pig), and others 

 in youth rather than in old age (e. g. the dog, horse, and ass). He has 

 been able to prevent its development in young dogs and in sheep by a 

 method of inoculation with spores or with the bacterium in its fission- 

 stage (bacillus). 



Four puppies were thus inoculated, and five were not. The first 

 batch resisted successfully four successive inoculations, while the non- 

 vaccinated puppies succumbed to the first inoculation in from two to 

 four days, showing great oedema of neighbouring parts. The first 

 batch developed slight fever, and in two cases slight oedema ; tho 

 other inoculations produced no effect on them. 



Of eleven sheep of the Lauragnais race, which is very susceptible 

 to the anthrax, five which were once inoculated with the poison died. 

 The remaining six were inoculated by the preventive method, and one 

 died from the eftects of a subsequent inoculation out of two thus 

 tested. The other five were re-vaccinated, and in a month's time were 

 found to show no signs even of illness when inoculated in various 

 ways. 



M. Toussaint has also performed experiments of injecting into the 

 blood of healthy sheep blood taken from an animal affected with 

 splenic fever, but deprived of the Bacillus anthracis. Taking blood 

 from a sheep just on tho point of death, when the bacillus has pre- 

 sumably produced all its possible eftect upon the vital fluid, M. 

 Toussaint proceeds to deprive it of the living bacillus in either of two 

 ways — by filtration, or by destroying the vitality of the organism. 

 The former he effects by mixing the blood with three or four parts of 

 water, and then passing it through about twelve layers of ordinary 

 filter-paper. The bacillus, in consequence of its large dimensions, is 

 entirely retained by this form of filter, as is proved by the fiict tliat 

 the filtrate no longer gives rise to the organism in a cultivating liquid 

 or in a living animal. Nevertheless, if injected in considerable quantity 

 into the circulation of a healthy sheep, it produces a true vaccinatin"' 

 influence ; that is to say, secures immunity from splenic fever. But 

 (what is further extremely interesting), in order tliat this cliaiige in 

 the constitution of tho sheep may be brought about, the lapse of a 

 certain time is essential. If a vaccinated sheep bo inoculated with 

 anthrax within a few days of the operation, it will die of splenic fever • 

 but if from twelve to fifteen days be allowed to elapse, complete immu- 

 nity is found to have been produced. 



Similar results followed from the injection of anthrax blood treated 

 by M. Toussaint's other method, which consists of maintaining it 

 for a considerable time at a temperature of 55° C, which has 

 the ofiect of killing "the bacillus; after which half per cent, of 

 carbolic acid is added, to prevent putrefaction of the liquid. Tho 

 blood treated in this way having been proved to be free from living 

 bacilli by negative results of an experiment upon a rodent, about four 

 c. c. are injected into the venous system of a sheep, with the effect of 

 producing the same protective influence against splenic fevor as is 

 ensured by tlic filtered blood. Tlusc experiments an; still in pro- 



