ARTIFICIAL SEPTICAEMIA IX AXIMALS. 113 



to produce a sufficient quantity of poisonous ptomaines to give rise 

 to progressive septic intoxication. 



ARTIFICIAL SEPTICAEMIA IN AXIMALS. In the latter part of 

 the seventeenth century, Kircher and Leuweuhoek claimed that 

 putrid substances contained minute microscopical worms which 

 caused the putrefaction. Perty and Naegeli assigned to the minute 

 organisms a vegetable origin instead of animalculae, as had been 

 previously done, and they were classified under the name of schizo- 

 mycetes. In 1857, Pasteur made the important discovery that 

 specific agents are the cause of the various forms of fermentation 

 and putrefaction. No discovery, perhaps, attracted such universal 

 and deep attention as Pasteur's theory of fermentation. This 

 theory was strengthened somewhat later by Lemaire's observa- 

 tion, that all fermentative changes in fluids are suspended on the 

 addition to the fluids of pheuic acid, from which he concluded that 

 fermentation must be due to living organisms. As for a long time 

 all septic affections were supposed to be caused by a process of fer- 

 mentation and putrefaction, these theories led to a diligent search 

 for microorganisms in the fluids of septic patients, and to experi- 

 mentation on animals with putrid substances. Koch, in his great 

 work on wound-infective diseases, published in 1878, described 

 two distinct varieties of septicaemia, one in mice and the other in 

 rabbits. In fifty-four infected mice he found small bacilli in the 

 interior of the white blood-corpuscles, and also in the capillaries 

 after they were set free by the destruction of the blood-corpuscles. 

 They were also found in the serous cavities and in the lymphatic 

 glands and vessels. The bacillus of mouse septicaemia was found 

 very difficult to cultivate, and Koch .first succeeded in cultivating 

 it upon a composition of gelatin with the aqueous humor of the 

 eye of the ox. The growth, however, was very feeble, and succes- 

 sive cultivations upon the same soil were uncertain. Later, Loef- 

 fler succeeded better with a nutrient medium composed of infusion 

 of meat, to which were added 1 per cent, of peptone and 0.6 per 

 cent, of common salt, the whole rendered faintly alkaline with 

 sodium phosphate. The bacilli appeared upon this clear and 

 transparent soil as opacities upon its surface. In rabbits he found 

 large oval micrococci free in the capillaries. The progressive 

 character of septicaemia was well shown by Koch and Davaine in 

 rabbits, as the latter could cause rapid death by injecting a single 

 drop of a mixture prepared by adding to a quantity of blood of a 

 rabbit which had died inoculated with a twenty-fourth generation, 

 diluted with one trillion times its quantity of pure water. 



Darwin believed that septicaemia could be produced in a more 

 and more virulent form with every successive inoculation from 

 animal to animal by the intensity of the virus being increased by 



8 



