in DIGESTION IN THE MOUTH AND STOMACH 181 



carbonic acid, hydrogen, methane or marsh gas, and occasionally 

 sulphuric acid (Kuhn, Boas, 1892). 



VII L The effects of complete or almost complete resection of 

 the stomach are highly important from the physiological point 

 of view, in order to form a clear concept of the significance as 

 a whole of its digestive and protective functions. 



The dog which survived the almost complete extirpation of its 

 stomach by Czerny and Kaiser, was able 2 months after the 

 operation to nourish itself on the mixed diet of a normal dog, 

 without vomiting or other disturbance. Its weight, 5850 grms. 

 previous to operation, rose in 9 months to 7000 grms. The 

 faeces were normal in constitution. When it was killed 6 years 

 later the post-mortem showed that only a small portion of the 

 stomach was left near the cardia, which had assumed the form of 

 a bladder filled with food. 



Ludwig and his pupil Ogata employed another method to 

 suppress the influence of the stomach on the digestion. They 

 introduced the food directly into the duodenum by a fistula made 

 near the pylorus, and to prevent the gastric juice from entering 

 the intestine, closed the pylorus by *a small rubber balloon, the 

 distension of which was regulated by means of water introduced 

 through the neck of the balloon, which projected from the gastric 

 fistula. The various foods introduced in large quantities directly 

 into the duodenum (beaten-up eggs, minced meat) were perfectly 

 digested without producing any disturbance. Two injections a 

 day sufficed to keep up the animal's weight. Microscopic examin- 

 ation of the faeces showed that the connective tissue of raw meat 

 was not perfectly digested ; boiled flesh was not digested, and was 

 excreted by the rectum after a few hours, little or not at all 

 modified. Raw pork was hardly digested at all, cooked pork was 

 to a much larger extent. These authors concluded that the 

 stomach was not absolutely necessary to the nutrition of the body, 

 either as a reservoir of food or in the formation of gastric juice. 



In 1893 Carvallo and Pachon successfully repeated the 

 almost total extirpation of the stomach on a dog ; in the first 

 20 days after the operation, the animal only tolerated milk, 

 which was imperfectly digested. Two months later it was still 

 unable to digest the connective tissue of meat. Three months or 

 more from the operation, it was estimated from the nitrogen 

 content of the food and the faeces, that the digestion of cooked 

 foods had become almost normal, while that of raw foods was 

 still imperfect. Five months after, the animal was made to eat 

 putrid meat without any ill effects, a fact which does not minimise 

 the antiseptic importance of the gastric juice, because after such a 

 long period some functional adaptation might ha,ve occurred in 

 the animal to compensate for the lapsed antiseptic function of 

 the stomach. 



