HOW ACIDS ACT IN PROMOTING PANCKEAT1C FLOW. 115 



It was conceivable that in the employment of 0'5 per cent, acid we 

 had not yet reached the highest degree of gland activity. On the 

 other hand, so far as one can judge from experiments not systematically 

 carried out, the sensitiveness of the pancreas is about as great as that of 

 the organs of taste, for a fluid which just tastes acid acts distinctly as 

 an excitant of the gland. The proportionate nature of the effects, and 

 the great sensitiveness to the influence of acids, confirmed us in the 

 belief that they behave not merely as general and indiscriminate 

 exciters, but as specific stimulants of the pancreas. This conclusion 

 appeared all the more forcible since the gastric glands remained per- 

 fectly indifferent to the same acids. We have, however, even more con- 

 vincing proofs. We have often compared the effects (Prof. SchirokicJi) 

 of such stimulating substances as pepper and mustard with those of 

 acids. With the former we could perceive no trace of exciting effect. 

 Decoctions of red pepper and mixtures of oil of mustard and water were 

 used as strong as they could be employed without producing vomiting. 

 The solutions caused distinct burning on the tongue but not the least in- 

 dication of a stimulating effect on the pancreas, while weak solutions of 

 acids invariably caused a flow of the juice at once. The experiments of 

 Dr. Gottlieb, which were performed on rabbits, with the same substances, 

 pepper and mustard, and which gave contrary results, must be inter- 

 preted in a different way to that which the author indicates. Obviously 

 there must have been an injury to the mucous membrane, caused by the 

 large doses of the substances in question, and the centripetal neives 

 themselves (not their terminal apparatus, which alone possesses specific 

 irritability) were in consequence excited. It appears to me that these 

 data suffice to give a positive answer to the question as to whether acids 

 are specific exciters of the pancreas or not. As a logical sequence to the 

 above, came the further conclusion that the gastric contents must have an 

 exciting effect on the gland by virtue of the acid reaction which they 

 possess. It naturally was not difficult to test this supposition. To begin 

 with, we convinced oxirselves that pure gastric juice was just as powerful 

 an excitant of the gland in question as an acid solution of equal strength. 

 Solutions of different sugars, of peptone, and of ovalbumen proved, when 

 introduced into the stomach, to be excitants of the pancreas only when 

 they possessed a strong acid reaction. If neutral or alkaline, their 

 secreto-motor effect was no greater than that of water, in some cases 

 even less. Finally, our hypotheses became fully established when we 

 succeeded in destroying the exciting effect of the gastric contents by 

 neutralisation of the mixture. When at the height of digestion, with a 

 free secretion of pancreatic juice, one introduces into the stomach of an 

 animal by means of the sound, or through a fistula, solutions of soda, 

 or lime-water, or pancreatic juice, after a few minutes, one always 



