BACTERIA AND CONTAGIOUS DISEASE, 71 



nature of the process called " fermentation." This 

 word is often employed very carelessly, and like "irrita- 

 tion," "nutritive irritability," "stimulus," and a number 

 of other terms, is supposed to account for many pheno- 

 mena, although its meaning has not been defined, 

 and those who use it do not tell us what they mean 

 by it. 



It appears then that bacteria germs grow and 

 multiply whenever a change takes place in the 

 solids and fluids of the organism which develops 

 compounds suitable for the pabulum of these living 

 bodies. From the fact that bacteria grow and 

 multiply not only in a few special fevers, but 

 in a great variety of different morbid conditions, 

 it is evident they have nothing to do with any 

 particular form of disease. All attempts to demons- 

 trate various constant species of bacteria, representing 

 different contagious diseases and many attempts have 

 been made have completely failed. There is greater 

 difficulty than would appear at first in testing the 

 matter experimentally, for it is probably impossible 

 to introduce bacteria in quantity into the blood of a 

 healthy animal without introducing at the same time 

 putrescent matters which by themselves would occa- 

 sion the most serious derangement. Active bacteria 

 introduced into a healthy wound or amongst the living 

 matter of healthy tissues, will die, although the most 

 minute germs present, which escape death, may remain 

 embedded in the tissue in a perfectly quiescent state. 



