MICROPHYTES FOUND IN THE BLOOD. 377 



trillionth, part of the original poison was sufficient to produce 

 death. Rabbits were found to be very susceptible ; guinea-pigs 

 somewhat less so. Rats were found to be capable of resisting a 

 considerable quantity. It was also observed by Davaine that 

 decomposing blood lost its virulent properties when exposed to 

 the air in a few days ; out of 27 animals inoculated with 1 to 

 T-^oth of a drop of bloody which had stood from 1 to 10 days, 13 

 died, whereas out of 26 animals inoculated with like material 

 which had stood from 11 to 60 days only 1 perished.^ 



M. Pasteur, bearing in mind the difi'erence between bacilli of 

 charbon and their ' spores' as regards tenacity of life, determined 

 to ascertain whether a similar condition did not exist in septi- 

 csemia. Three animals which had died of charbon were examined 

 — a sheep, dead 6 hours ; a horse, dead 20 to 24 hours ; and a 

 cow, dead over 48 hours. The blood of the sheep, which had 

 only recently died, contained charbon-bacteridia only ; that of the 

 horse bacteridia, together with " vibriosis de j^'^^f'i'f^f'Jction ; " 

 whereas that of the cow contained only " vibrions " of the kind 

 last mentioned. 



Inoculations with the blood of all three animals were followed 

 by death. The autopsies (conducted immediately after death) of 

 the guinea-pigs which had died after inoculation with material 

 from the two last-mentioned animals, revealed extensive inflam- 

 mation of the muscles of the abdomen and limbs, with accumu- 

 lations of gas here and there, the liver and lungs discoloured, the 

 spleen normal in size, but often diffluent, the blood of the heart 

 not coagulated, although this characteristic was more evident in 

 the liver — quite as evident as in any case of charbon. Strange 

 to say, writes M. Pasteur, the inflamed muscles contained mobile 

 " vibrions ; " these were still more numerous in the serosity of the 

 abdominal cavity, and some of them were of great length.^ A 

 drop of this fluid would rapidly kill an inoculated animal, but 

 ten or twenty had no effect after it had been filtered. The 

 'vibrions' are not found in the l/hod till after or very shortly 

 before death, and such blood is said to manifest no virulent 

 properties if taken direct from the heart without contamination 

 with the tissues outside it. 



' "Inoculation de la matiere septique," 'Bulletin de I'Aeademie de 

 Science,' November, 1872, January, 1873 ; cited by Birch-Hirschfeld, loc. 

 cit,, p. 173. 



^ M. Pasteur, on noticing this condition, asks why it is that a circum- 

 stance so general in deaths of this kind had hitherto escaped notice ; and 

 replies to the query, that it was doubtless owing to the attention of previous 

 observers having been devoted solely to the blood. It seems strange that 

 M. Pasteur's specially selected coUaborateur, and adviser in medical matters, 

 did not inform him that this very api>earauce was about the best known of 

 all the phenomena characterising septic poisoning. 



