160 Transactions of the Royal Society of Victoria. 



yet this is by no means an idle enquiry. For although 

 within the body, under normal conditions, an alkaline, or at 

 least a neutral reaction of the chyme may be secured, almost 

 immediately after it has passed out of the stomach, there is 

 sufficient practical reason for desiring to know whether 

 the activity of the pancreatic ferments is stopped by the 

 presence of an acid, and if so, in what degree of concentration. 

 For these ferments have now entered largely into commerce, 

 and are used in various ways as helps to digestion. It is 

 important to know the limits to the range of their action, so 

 that agents which are powerful for good, when rightly used, 

 may not be misapplied. And further, it is interesting to 

 know the fate of such agents, when subjected to conditions 

 other than those they ordinarily meet with; whether, that is 

 to say, their powers are only kept in abeyance temporarily, 

 or are completely destroyed. 



Experiments with the view of testing these points have 

 become possible, only since good and reliable forms of these 

 ferments have been prepared, and the importance of having 

 them tested is increased by the fact, that they are now 

 largely used in practical medicine. The first of these uses is 

 in the preparation of artificially digested food, for adminis- 

 tration in cases where digestion is greatly impah^ed, or where 

 for any reason it is desired to spare the labour to the stomach 

 involved in carrying on the process of digestion. For this 

 purpose, the pancreatic ferments have a marked superiority 

 over pepsin, which acts only on albumens, and does so only 

 in acid solutions. But when it is proposed further to give 

 these pancreatic preparations internally, as a help to 

 digestion, the question is at once raised, whether there 

 is not simple waste in doing so, there being considerable 

 grounds for supposing that their powers are in complete 

 abeyance in the presence of the acid of the gastric juice. 

 And even supposing that this abeyance of acti\dty is proved 

 to come about in the stomach, there remains the further 

 question, whether the ferments themselv^es are actually 

 destroyed by continued exposui^e to the action of the acid 

 and pepsin of the gastric juice, or are capable of resuming 

 activity when an alkaline reaction is again brought about 

 in the duodenum. It was for the purpose of testing 

 these points that the following experiments were de\dsed. 

 The preparation tested was the article of well-established 

 activity, known as zymine, a powder containing the 

 mixed ferments formed by the [jancreas. In the stomach 



