THANSACTIOXS OF SECTION I. 



821 



11. Electrostalical Experirrwnts on Nerve Sirmdatincf the effects of 

 Electric Rays. By Professor Jacques Loeb. 



12. 



The Gastric Inversion of Cane Sugar hy Hydrochloric Acid} 

 By Professor Graham Lusk. 



For thirty-five years it has been shown upon the lecture table of ^'oit that a 

 €•3% hydrochloric acid solution at the temperature of the body has the power of 

 rapidly inverting cane sugar. After feeding an animal with cane sugar, that and 

 invert sugar are found in the stomach, while only invert sugar is to be detected in 

 the intestinal canal. No inverting enzyme has been fouud in the stomach similar 

 to that present in the small intestines. The question to be solved was this : is 

 the acid of the gastric juice a sufficient agent to accomplish such inversion of cane 

 sugar as takes place within the stomach ? The following table shows in per cent, 

 the amount of cane sugar inverted after standing diiferent lengths of time, with 

 different strengths of acid, at a temperature of 38-40° C. 



The results show the stronger the acid the greater the inversion. In general 

 about the same percentage of inversion is obtained with a 6% sugar solution as 

 with a 091% solution. The amount of cane sugar inverted by the same acid is 

 thus proportional to the strength of the sugar solution. Hence, as the sugar 

 solution becomes more and more changed by inversion, the quantity to be acted 

 on becomes smaller, and therefore the quantity inverted grows less. This is accord- 

 ing to Wilhelmy's law of chemical change. It has also been determined that 

 proteid (white of eggs) and proteolytic digestive products in acid combination with 

 hydrochloric acid (i.e., when the solution gives no tropseolin reaction) have almost 

 the same inverting action as free hydrochloric acid. Comparing these experiments 

 with results already obtained from living animals, the conclusion is drawn that 

 •the acidity of the gastric juice is itself sufficient to produce such inversion as takes 

 place in the stomach. Many of the analyses given above were made by Dr. S. J. 

 Ferris. 



SATURDAY, AUGUST 21. 

 The Section did not meet. 



^ The Paper will be published in the Am, Journ. of Physiology. 



