THE ACID EFFECT UPON PANCREATIC SECRETION. 1 1 



organism. These difficulties are all removed when we consider the 

 relationships of the digestive juices just discussed. The acid gastric 

 juice causes secretion of pancreatic fluid l>y its acidity and in 

 direct proportion to it; that is to say, while the acid constituent of 

 the sodium chloride is taken up by the peptic glands and then passed 

 on into the cavity of the stomach, the basic element, the sodium, 

 serves for the preparation of pancreatic fluid. And thus the two 

 constituents of the sodium chloride meet again in the alimentary canal 

 and reproduce the salt. Recently this explanation has received support 

 from the experiments of .Dr. Walther. If the acid excites a ilow of 

 pancreatic juice, with the object amongst others, of neutralising itself, 

 we should in consequence expect to meet with variations in the 

 alkalinity of the juice, apart from the content of ferment, and deter- 

 mined by the acidity of the exciting fluid ; and this is indeed the case. 

 Determinations of the amount of ash, as well as titration both of the 

 ash and of the unaltered pancreatic juice, have incontestablv shown that 

 a connection exists between the nature of the secretory excitant and 

 the amount of inorganic substance in the pancreatic fluid. The juice 

 excited by acid solutions shows a very unimportant amount of organic 

 substances with a maximal content of inorganic ; in fact, the quantity of 

 the latter is two or three times as great as that of the former. It 

 shows also a very high degree of alkalinity both in the ash and in the 

 juice itself. Thus the rapidity of the secretion has no decided influence, 

 the " acid " juice retains its characteristic properties even when the 

 hourly quantity of secretion varies. This occurrence is perfectly 

 analogous to one previously described. In the first lecture we saw that 

 the ferments of the juice adapted themselves to the kind of food ingested 

 at the time being. With bread the amylolytic ferment, and with milk 

 the fat-splitting ferment, was found to be increased. Likewise here, an 

 acid-exciting substance evokes the production of alkali, while the 

 organic constituents which are not required are extraordinarily reduced. 

 The juice, however, which is poured out on acids is never wholly 

 deprived of its ferment-properties. This shows that the relation- 

 ship just mentioned is only one of relative importance. The juice is 

 always produced for digestive purposes, and never merely for the 

 neutralisation of acids. 



By a fuller study of the alkalinity we shall probably soon be in a 

 position to indicate that part of the general flow of pancreatic fluid 

 which is evoked by the acid, or, in other words, to know if the acid 

 always plays a part in the production of the juice, [t appears, for 

 instance, that " flesh juice " secreted by the pancreas during the first 

 hours after partaking of this food approaches very nearly in inorganic 

 constituents to the " acid juice." This harmonises beautifully with 



