DIGESTION IN THE STOMACH 153 



gastric juice, and was then pulled out. Such methods were 

 obviously crude, and led to but imperfect results. At the pres- 

 ent time, to study gastric contents a light meal is given, and 

 after a time the stomach content is pumped out with a stomach 

 pump. This material consists of gastric juice mixed with food, 

 but the method may give data valuable for diagnosis. 



The first successful study of gastric juice and the condi- 

 tions causing its flow was made possible by an accident which 

 occurred in 1822 on the Island of Mackinac. Alexis St. Mar- 

 tin, a Canadian coureur du bois, was accidentally shot in the 

 abdomen. The bullet passed through the stomach, and when 

 the wound healed, a passageway was left from the stomach to 

 the exterior. St. Martin recovered and lived for a long time 

 in perfect health. He came under the care of Dr. William 

 Beaumont, an American army surgeon, who recognized the 

 exceptional opportunity to study the problems of gastric diges- 

 tion, and made a long series of careful investigations. Two 

 Europeans developed the same method of study by producing 

 artificial openings or " fistulas " into the digestive tract of dogs. 

 The Russian, Pavlov, has brought the technique of the method 

 to its highest stage of perfection. An incision was made into 

 the stomach, and the cut sewed up in such a way as to produce 

 a small pouch, or "little stomach" separated from the main 

 stomach cavity, but still supplied with blood vessels and nerves. 

 From this pouch, a silver tube led to the exterior. If gastric 

 juice was poured out into the small pouch, it could be drawn off 

 to the exterior and its composition and properties studied. These 

 observations made on dogs have been supplemented by occa- 

 sional investigation on human beings when restriction of the 

 esophagus or other causes made it necessary to make an open- 

 ing into the stomach from the exterior. By the use of such 

 methods a large number of investigators have studied the prob- 

 lems, of gastric secretion and digestion. The results of these 

 studies are summarized in the following discussion. 



Causation of Flow of Gastric Juice. The interior of the 

 stomach, when no food is present, is pale pink and velvety in 



