Proceedings. 23 



I think it would be out of place to enter into detail 

 respecting each of these Fungi, and the diseases produced by 

 them ; I will therefore, in conclusion, mention only a few 

 facts connected with their history, without any attempt at an 

 orderly arrangement, 



1st. They are minute in size. Mr. Nelson says : — " The 

 average size of the Bacillus of tubercle is 1 -9000th of an 

 inch long by 1 -60,000th of an inch broad, so that 32,400 

 would pack into a cubical bos whose side was 1- 1000th of an 

 inch. The spores of many- pass our finest filters, and elude 

 the power of our best microscopes." 



2ndly. Multiplication or increase. — It has been reckoned 

 that by fission or division one individual can produce 

 8,388,408 in twenty-four hours. When the increase is by 

 spores, it is more rapid. 



Srdly. Cultivation and Attenuation. — I will give only the 

 results of Pasteur's experiments on Anthrax. Grown on 

 chicken-broth, this fungus produces spores in twenty-four 

 hours, and afterwards becomes reduced wholly to germ-dust. 

 If inoculated, this produces the disease, and causes death. 

 But if grown at a lower temperature, 42° to 43° C, it produces 

 threads only, and is entirely free from germs. In a month 

 or six weeks the culture dies, and cannot be propagated in 

 fresh broth. As the vitahty of the microbe decreases its 

 virulence diminishes, and this is proportioned to the time 

 which has elapsed, that of the eighth day being less than the 

 sixth, and the sixth less than the fourth ; and each of these 

 constitutes a vaccine, i. e., a virus capable of producing a 

 milder form of the disease. I may mention the result of an 

 experiment on fifty sheep. Twenty-five were vaccinated with 

 attenuated virus. A fortnight afterwards the fifty sheep were 

 inoculated with the most virulent virus of anthrax. The 

 twenty-five vaccinated sheep resisted the infection ; the 

 twenty-five unvaccinated died of splenic fever within fifty 

 hours. The value of this discovery you will be able to 

 estimate from the fact that in France alone sj)lenic fever 

 every year destroys animals of the value of 20,000,000 frs. 



4thly. Germicides. — There are many other things in con- 

 nection with my subject to which I might allude, but I will 



