REHFUSS— THE NORMAL GASTRIC SECRETION. 463 



examination, I have called the " fractional examination or determi- 

 nation of gastric digestion," because it consists in removing at in- 

 tervals a fractional portion of the actively changing gastric contents 

 for examination. From the material which is removed by aspira- 

 tion, by newer methods a complete chemical, bacteriological and cyto- 

 logical examination may be made and curves constructed represent- 

 ing the progress of gastric digestion. 



By means of this tube, the first important observation which we 

 made was the nature of the material found in the empty stomach. 

 It has been generally considered that this material should not exceed 

 20 c.c. in health. We found in a study of over 100 normal medical 

 students, that the quantity of material in the empty stomach prac- 

 tically always exceeded this point and in the above series, the average 

 was 52.14 c.c, more than twice the quantity formerly considered 

 normal. We found furthermore that this material was in most in- 

 stances a physiologically active secretion capable of inducing gastric 

 digestion and giving as average figure for the above series a total 

 acidity of 29.9 in terms of N/io NaOH necessary to neutralize 100 

 c.c. of secretion (phenolphthalein) and 18.5 free acidity (Sahl 

 method). Pepsin determination in 53 cases gave an average of 

 (2.8). We were further able to demonstrate by means of a special 

 method devised in our laboratories the presence of trypsin almost 

 constantly in the residuum, which was shown to be inversely propor- 

 tional to the free acidity. 



In other words we found at whatever time we examined the 

 stomach regardless of the presence or absence of food a physio- 

 logically active secretion in the stomach. If as was performed on 

 several occasions, we removed the complete residuum and then with- 

 out introducing food in the stomach examined the organ somewhat 

 later, a physiologically active secretion could be removed even though 

 in digestive power it was lower than the material seen during the 

 digestive periods. In health therefore it is correct to assume that 

 there is always a minimal secretion in the stomach which at regular 

 intervals undergoes perturbations due to the influence of hunger, 

 psychic influences of sight, taste, and smell of food, and finally the 

 complex digestive cycle following the introduction of food into the 

 stomach. 



PROC. AMER. PHIL. SOC, VOL. LV, CC, JULY lO, I916. 



