'650 FRAGMENTS OF SCIENCE 



self as it does to the scientifically trained mind, the anti- 

 septic system has struck deep root in Grermany. 



Had space allowed, it would have given me pleasure 

 to point out the present position of the "germ theory" in 

 reference to the phenomena of infectious disease, distin- 

 guishing arguments based on analogy — which, however, 

 are terribly strong — from those based on actual observa- 

 tion. I should have liked to follow up the account I 

 have already given* of the truly excellent researches of 

 a young and an unknown German physician named Koch, 

 on splenic fever, by an account of what Pasteur has re- 

 cently done with reference to the same subject. Here we 

 have before us a living contagium of the most deadly 

 power, which we can follow from the beginning to the 

 end of its life cycle.' We find it in the blood or spleen 

 of a smitten animal in the state, say, of short motionless 

 rods. When these rods are placed in a nutritive liquid 

 on the warm stage of the microscope, we soon see them 

 lengthening into filaments which lie, in some cases, side 

 by side, forming in others graceful loops, or becoming 

 coiled into knots of a complexity not to be unravelled. 

 We finally see those filaments resolving themselves into 

 innumerable spores, each with death potentially housed 

 within it, yet not to be distinguished microscopically from 

 the harmless germs of Bacillus subtilis. The bacterium of 

 splenic fever is called Bacillus Anihracis. This formida- 

 ble organism was shown to me by M. Pasteur in Paris 

 last July. His recent investigations regarding the part it 

 plays pathologically certainly rank among the most re- 



* "Fortnightly Review," November, 1876; see article "Fermentation." 



* Dallinger and Drysdale had previously shown what ski^l and patience can 

 accomplish, by their admirable observations on the life history of the monads. 



