22 PA THOGENIC BA CTERIA. 



laboratory were organized bodies. If these were planted 

 in sterile infusions, abundant crops of micro-organisms 

 were obtainable. By the use of more refined methods 

 he repeated the experiments of Schwann and others, and 

 showed clearly that "the cause which communicated life 

 to his infusions came from the air, but was not evenly dis- 

 tributed through it." 



Three years later he showed that the organized cor- 

 puscles which he had found in the air were the spores or 

 seeds of minute plants, and that many of them possessed 

 the property of withstanding the temperature of boiling 

 water a property which explained the peculiar results 

 of many previous experimenters, who failed to prevent 

 the development of life in boiled liquids enclosed in 

 hermetically-sealed flasks. 



Chevreul and Pasteur (about 1836) proved that animal 

 solids did not putrefy or decompose if kept free from 

 the access of germs, and thus suggested to surgeons that 

 the putrefaction which occurred in wounds was due rather 

 to the entrance of something from without than to some 

 change within. The deadly nature of the discharges 

 from these wounds had been shown in a rough manner 

 by Gaspard as early as 1822 by injecting some of the 

 material into the veins of animals. 



Examinations of the blood of diseased animals were 

 now begun, and Pollender (1849) an d Davaine (1850) 

 succeeded in demonstrating the presence of the anthrax 

 bacillus in that disease. Several years later (1863) Da- 

 vaine, having made numerous inoculation-experiments, 

 demonstrated that this bacillus was the materies morbi 

 of the disease. 



Tyndall enlarged upon the experiments of Pasteur, 

 and very conclusively proved that the micro-organ ismal 

 germs were in the dust suspended in the atmosphere, not 

 ubiquitous in their distribution. His experiments were 

 very ingenious and are of interest to medical men. First 

 preparing light wooden chambers, with one large glass 

 window in the front and one smaller window in each 



