DURATION OF STOMACH DIGESTION 2OI 



said to be digested ; for they are either liquid or in solution in water and 

 are capable of direct absorption and assimilation. In regard to most of 

 the inorganic salts, they either exist in small quantity in the ordinary 

 water taken as drink or are united with organic nitrogenous substances. 

 In the latter case, they become intimately combined with the organic 

 matters resulting from gastric digestion. It has been noted that the 

 various peptones contain the same inorganic salts that existed in the 

 nitrogenous substances from which they were formed. 



Duration of Stomach Digestion. Inasmuch as comparatively few 

 articles, and these belonging exclusively to the class of organic nitroge- 

 nous substances, are completely dissolved in the stomach, it is evident 

 that the length of time during which food remains in this organ, or the 

 time occupied in the solution of food by gastric juice out of the body, 

 does not represent the absolute digestibility of different articles. 



There has certainly never been presented so favorable an opportu- 

 nity for determining the duration of gastric digestion as in the case of 

 St. Martin. From a great number of observations made on digestion 

 in the stomach itself, Beaumont came to the conclusion that " the time 

 ordinarily required for the disposal of a moderate meal of. the fibrous 

 parts of meat, with bread etc., is three to three and a half hours." The 

 observations of F. G. Smith, made upon St. Martin many years later, 

 gave two hours as the longest time that aliments remained in the 

 stomach. In a case of intestinal fistula reported by Busch, it was 

 noted that food began to pass out of the stomach into the intestines 

 fifteen minutes after its ingestion and continued to pass for three or four 

 hours, until the stomach was emptied. The average time that food re- 

 mains in the stomach after an ordinary meal may be stated to be between 

 two and four hours. 



Milk is one of the articles digested in the stomach with greatest 

 ease. Its highly nutritive properties and the variety of its nutritious 

 constituents render it most valuable as an article of diet, particularly 

 when the digestive powers are impaired and when it is important to 

 supply the system with considerable nutriment. Eggs are likewise 

 highly nutritious and are easily digested. Raw and soft-boiled eggs 

 are more easily digested than hard-boiled eggs. " Whipped " eggs are 

 apparently disposed of with great facility. As a rule the flesh of fish 

 is more easily digested than that of the warm-blooded animals. Oysters, 

 especially when raw, are quite easy of digestion. The flesh of mam- 

 mals seems to be more easily digested than the flesh of birds. Of the 

 different kinds of meat, venison, lamb, beef and mutton are easily 

 digested, while veal and fat pork are digested with difficulty. Soups 

 usually are very easily digested. The animal substances that are 



