848 PHYSIOLOGY 



that the food remains in the stomach. In the animal with a pyloric 

 fistula, one to two minutes after the meal had been taken, a few 

 drops of alkaline fluid were extruded from the opening. From three 

 to eight minutes after the conclusion of the meal small quantities 

 of clear acid gastric juice were repeatedly extruded. The first ad- 

 mixture of the food with the outflow from the fistula occurred at eight 

 to twelve minutes after the completion of the meal, and after this 

 time the pylorus continued to open at regular intervals of ten to 

 forty seconds, discharging each time a small amount of fluid com- 

 posed of particles of undigested bread mixed with gastric juice. 

 One and a half hours later the pylorus began to open less regularly 

 and the fluid became of a more pasty consistence, devoid of lumps 

 of undigested bread. In the fourth, fifth, and sixth hours after the 

 meal the pylorus opened only once every one or two minutes, and 

 towards the end of this period the fluid extruded was clear. The 

 following Table shows the percentage amount of food taken which 

 had left the stomach at the end of each hour after the meal : 



First hour . . . . . .32-6 per cent. 



Second hour ..... 17-9 



Third hour . . . . . . - 29-5 



Fourth hour 1-87 



Fifth hour 6-66 



Sixth hour 4-21 



The large proportion of the ingested food leaving the stomach 

 during the first two or three hours can hardly be regarded as normal. 

 Since in these experiments there was a free outflow from the 

 pylorus and the food was not allowed to enter the duodenum, the 

 local reflex, evoked by the presence of acid in the duodenum, was 

 absent. The gastric contents obtained in this way were analysed in 

 order to find what changes had been wrought on the food by the 

 gastric juice. It was found that 32 per cent, of the bread had been 

 brought into solution. This solution had affected the proteins more 

 than the carbohydrates. Thus 67 per cent, of the nitrogen had been 

 brought into soluble form, consisting chiefly of albumoses and peptones. 

 No amino-acids were formed. Only 25 per cent, of the starch of the 

 bread had been rendered soluble, and of this, 21 per cent, was in 

 the form of dextrine and 4 per cent, in the form of sugar. No 

 absorption, however, either of the digested proteins or of the digested 

 carbohydrates was ever found* to take place in the stomach. 



DUODENAL DIGESTION. The influence exerted by the pan- 

 creatic juice, bile, and succus entericus, poured out on the food 

 in the duodenum, was studied by analysis of the intestinal contents 

 leaving the intestine by a fistula, either at the lower end of the duo- 

 denum, or in the jejunum, or in the ileum. From the duodenal 



