178 Disease Generated by Infusoria. 



are very short as well as very scarce, but they will soon be seen 

 to multiply and grow rapidly, their complete evolution only 

 requiring a few hours for its accomplishment. A rabbit, 

 the blood of which merely exhibited a few bacteriums, from 

 four to six thousandths of a millimeter in length, died at 

 the end of four hours, and its blood, which was examined im- 

 mediately afterwards, contained a considerable number of bac- 

 teriums, some of which, larger than any I had previously seen, 

 reached the five-hundredth of a millimeter in length. 



" In some animals the bacteriums are generally found 

 larger than in others, but not presenting any other difference. 

 In such cases their number was usually less. The length 

 which the filaments sometimes acquired suggests their classi- 

 fication among the Confervas ; but I omit, for the moment, the 

 discussion of this question, as it has little importance yi the 

 present inquiry. 



" The number of the bacteriums varies much between one 

 animal and another. After my first inoculations this number 

 decreased very rapidly, and they became eight or ten times 

 less than the blood corpuscles. This led me to believe that 

 their propagating power dwindled in rabbits, but I was after- 

 wards convinced that such was not the case, as in a series of 

 eleven individuals, one inoculating the other in succession, the 

 blood of the tenth contained myriads of bacteriums like that of 

 the first. I can only explain these variations by the changes 

 in atmospheric temperature which occurred during my experi- 

 ments. 



" When the infected animal dies the bacteriums cease to 

 multiply or grow, and in blood removed from its vessels they 

 become destroyed or transformed. The loss of their primitive 

 aspect is accompanied by loss of the power of propagating 

 themselves in a living animal. Two inoculations effected, one 

 with sheep's blood kept for eight days, the other with rabbit's 

 blood kept six days, neither occasioned the spleen disease nor 

 the formation of bacteriums. 



" When fresh blood is rapidly dried in free air, the bac- 

 terid ms preserve the faculty of inoculation, as I found in many 

 experiments. The dried blood can sustain a temporature of 

 95 to LOO' (C.) without this faculty being destroyed. 



" Some fresh blood was enclosed in a tube and kept for ten 

 minutes in water in ebullition. This blood being afterwards 

 introduced under the skin of a rabbit, led to its decease, with 

 formation of Imeteriums in thirty-one hours. Cooking is there- 

 fore insufficient to destroy their vitality. 



" J 11 four! con rabbits the mean duration of life after inocu- 

 lation was forty hours ; the shortest period being twenty-eight 

 hours, and the longest sixty-seven. The duration was longer 



