232 Dynamic Theory. 



necessarily suspended half the year. During this suspension the food 

 must be in a condition to escape being dissolved and wasted. So that 

 starch is an essential sort of food for plants, and diastase is an essen- 

 tial sort of an agency for breaking it up when it is needed. 



It would appear that the soluble ferments cannot be regarded as true 

 organisms, although they are organic in their composition and always 

 found in nature in association with organisms. As already mentioned, 

 their action is imitated by various chemical agents acids or alkalies. 

 A small quantity of sulphuric acid will act to alter a great quantity of 

 fermentable matter, and the acid will continue to act indefinitely with- 

 out diminution. In like manner a small amount of the natural ferment 

 can modify a vastly greater quantity of starch. According to experi- 

 ments of Pay en and Persoz, 2000 parts of starch can be altered and 

 turned to sugar by one part of diastase, and if the glucose be removed as 

 it is formed, the process may continue apparent!}*" indefinitely, although 

 there appears to be a slight deterioration in the force of the diastase 

 after prolonged service. The yeast plant, mucors and other parasitic 

 organic ferments grow at the expense of the fermentable matters in 

 which they act and which they alter, but it is not so with the diastases. 

 Their presence merely is all that is required. This fact, together with 

 the great rapidity of their action, often, as it is said, instantaneous, 

 shows that the results they bring about are not due to their growth or 

 consumption of a part of the materials. One diastase may be able to 

 act upon several different sorts of glucosides or fermentable matters, 

 producing quite different sets of results. Thus emulsin or synaptase, 

 the ferment contained in almonds, acts upon amygdalin, resolving it 

 into glucose, benzoyl hydride, and prussic acid ; it resolves salicin into 

 glucose and saligenin ; helicin into glucose and salicylic hydride ; arbu- 

 tin into' glucose and hydroquinone ; phlorizin into glucose and phlore- 

 tin ; esculin into glucose and esculetin ; daphnin into glucose and daph- 

 netin ; and several others. The origin of the diastase appears to be in 

 the permanent glandular organs of the plants or animals where it is 

 found, and it is a manufactured product of such an organism. It fur- 

 ther appears when manufactured, in some cases at least, to become 

 incorporated in the tissues of the gland where it originates, so that to 

 get the diastase we have only to chop up the gland. The use of the 

 rennet stomach of a calf in curdling milk in cheese-making illustrates 

 this, the organ itself possessing the diastase. The same is proved by 

 the facts in relation to the conversion of glycogen into sugar in the 

 liver, also by the preparation of diastase from germinated barley men- 

 tioned above. 



The 'manner in which the diastase acts is not clear. But it seems tol- 

 erabl} T certain that the diastase itself does not enter into combination 



