74 MISSOURI BOTANICAL GARDEN. 



ture shows a strong arni}^ of names among the opponents, 

 as well as the supporters, of this proposition. But perhaps 

 the conviction of Pasteur that hydrophobia is a germ dis- 

 ease, capable of being communicated by the microbes of 

 artificial cultures, and, like small-pox and anthrax, prevent- 

 able, to a certain degree, by a process comparable to vac- 

 cination, will be most surprising to the layman. 



These are all diseases of man, though several of them are 

 common to, or originate with, the domestic animals, like 

 that dreaded and incurable disease of the horse, — glanders. 

 Others of a similar character are confined to one or another 

 of these animals. As examples, hog cholera, the chicken 

 plague, and the Texas fever of cattle, may be named. The 

 silk interest was at one time threatened with complete de- 

 struction by a germ disease of the worms. These diseases, 

 and the list is far from exhausted, are said to result from, 

 or are consequences of, a fermentation of living tissues cor- 

 responding to the putrefaction or similar changes which 

 other bacteria cause in dead animal or vegetable matter. A 

 certain class of them, including cholera and typhoid fever, 

 are spoken of as filth diseases, from their frequent dissem- 

 ination by contaminated drinking water. Certain it is, that 

 the germs of many propagate in filth, and are never far from 

 us ; and the frequent insufficiency of quarantine shows how 

 difficult the exclusion of others may be. 



To know, so far as he may, the true nature of these germs 

 or microbes, the manner of their development and repro- 

 duction, and the conditions of air, sewerage, food, drink 

 and personal intercourse, which favor their propagation, and 

 of the human body which render it susceptible to their at- 

 tacks, as well as the means of circumventing or destroying 

 them, is the duty of every young man entering the profes- 

 sion of medicine. Chairs of bacteriology are already being 

 established abroad, and liberal sums are placed in the hands 

 of experts for the purpose of investigating the subject of 

 contagious diseases. In this country, lectures on bacteria 

 and the germ theory of disease are given as an addition to 



