t 74" 1 



destroys their power. .In these two respects they resemble 

 microbes. 



1.284. Microbes or ordinary ferments are living organ- 

 ism which are capable of growing and multiplying. They 

 also cause fermentation. With a high power microscope they 

 can be actually seen. Enzymes themselves are the product 

 of microbes. 



1.285. Fermentation. - Fermentation is divided into three 

 classes : (I) Fermentation proper e. g. t (a) Vinous or 

 saccharine fermentation caused by the yeast fungus and 

 certain moulds resulting in the production of alcohol ; (b) 

 Acetic fermentation caused by the microderma aceti fungus 

 acting on alcoholic solutions ; (c) Lactic fermentation caused 

 by Bacillus lactis acting on the sugar of milk ; (d) Butyric 

 fermentation caused by the Bacterium butyricus acting on 

 the fat globules of milk. (II) Putrefaction or growth of 

 saprophytic rot-germs on dead bodies of plants or animals. 

 This is accompanied by the production of mal-odorous gases 

 containing sulphur, phosphorus, &c., also of toxines, 

 ptomaines, &c., which are highly poisonous substances. A 

 putrefactive germ produces in milk (or in ice-cream) a toxine 

 called tyrotoxicon which is able to poison people to death. 



(III) Pathogenic fermentation is caused by disease producing 

 germs living in the tissues of plants and animals. They 

 also produce toxines or poisonous substances which are 

 highly deliterious to the life of the plant or the animal. It 

 is not by the blocking up of capillaries caused by an 

 abundant growth of Bacillus anthracis, but by the production 

 of a poisonous substance by a few of the Bacilli, that the 

 animal dies so suddenly when it is attacked by anthrax. 



(IV) Fermentation caused by unorganised ferments must be 

 distinguished from the above three classes of true fermenta- 

 tion caused by microbes. 



1.286. Antitoxin treatment. The fever which accom- 

 panies most diseases due to pathogenic microbes is the 



