CH. XI] THE ENZYME THEORY OF DISEASE 165 



{vide p. 60) it can be proved that not only is the fermentation 

 of different carbohydrates effected by distinct and appropriate 

 ferments but each of the several stages in the fermentation 

 of a single carbohydrate — such as the formation of acids and 

 the production from these acids of gas — is carried out by its 

 distinct and appropriate ferment. Moreover different carbo- 

 hydrates yield on fermentation different acids and each 

 different acid requires to be acted on by a special ferment 

 before it becomes split up into gaseous products. If such a 

 comparatively simple result as the production of acid and 

 gas in various carbohydrate media requires the co-operation 

 of so many distinct ferments, the extremely complex and 

 diverse results of the bacterial invasion of the body would 

 appear to demand proportionately greater complexity and 

 diversity in the zymotic agents causing them. 



We have seen that the enzymes concerned with the fer- 

 mentation of particular carbohydrates are definitely associated 

 with certain vegetable and bacterial cells but not with others. 

 For example, many yeasts are able to invert sugar but only 

 three yeasts are known which are able to ferment lactose. 

 Proteolytic ferments are, likewise, associated only with 

 certain vegetable cells, such as the papain. Proteid-splitting 

 and lactose-splitting ferments are associated with certain 

 bacteria of the typhoid-coli group but not with others. It is 

 conceivable that, in precisely the same way, the agencies 

 responsible for certain definite symptoms in disease might be 

 definitely associated with some bacterial cells but not with 

 others. 



A further suggestion occurs to one at this point. If the 

 enzyme responsible for one particular symptom of a disease 

 can be dissociated from the specific organism of that disease, 

 should we not expect to be able, by suitable methods, to 

 dissociate from the organism not one only but all the enzymes 

 causing the various symptoms of the disease in question ? 



15. If such a complete dissociation were practicable it 

 should be possible to accomplish two things ; in the first 

 place, to deprive an organism of its power to produce a single 

 one of the symptoms of the disease associated with it and, in 



