52 THE MICROSCOPE. 



nal. Dr. D. E. Salmon argues strongly in favor of the germ theory 

 of disease and attempts to prove the identity of the virus of carbon 

 is a bacterium. He offers the following propositions in support of 

 his argument: 



1. Blood and pieces of spleen, or lymphatic glands, if dried as 

 soon as possible, after the death of the animal, soon lose their ac- 

 tivity — the smaller particles in twelve to thirty hours, and all within 

 five weeks. When their inactivity is proved by inoculation, cultiva- 

 tion-experiments show that the Bacillus has perished. 



2. Such pieces of spleen, or glands, which have been dried, 

 slowly, in a warm room, may retain their virulence for, certainly, 

 four years. These are found to contain spores, which may be cul- 

 tivated, and which grow into filaments that again form spores. 



3. If a bottle, or test-tube, is filled with carbon blood, tightly 

 corked, and placed in an incubator at 35°, it very soon has an ex- 

 tremely disagreeable odor of putrefaction, and, within twenty-four 

 hours, the rods have disappeared, and the fluid is no longer capable 

 of producing the disease when inoculated. This is, evidently, due 

 to the absorption of the available oxygen by the septic bacteria, as 

 may be rendered clear by the next two paragraphs. 



4. If a drop of such carbon blood is placed on a slide, and 

 covered, and the cover cemented air-tight, the rods grow until the 

 oxygen is exhausted, as shown by the spectroscope, they then remain 

 stationary, and, in a few days become granular, and disintegrate 

 without forming spores. Such blood is no longer capable of pro- 

 ducing carbon. 



5. If the carbon blood be placed in a watch-glass where there 

 is free access of air, and then kept in an incubator at a proper tem- 

 perature, the putrefaction goes on as before, and swarms of micro- 

 cocci and bacteria appear. The development of the Bacillus 

 .anlhiacis is accomplished, however, as though no other organisms 

 were present, the spores are formed, and sink to the bottom, and in- 

 oculations produce the disease for a long time afterward (at least 

 twelve weeks, as shown by experiment.) 



6. When substances containing the Bacillus rods, alone, are 

 somewhat diluted witli distilled or well-water, the development of 

 the rods is not stopped; but, if the dilution is excessive, the organ- 

 ism is soon destroyed, and, after thirty hours, inoculations fail to 

 produce the disease. That is, the actively-growing organism re- 



