DIGESTION OF FOOD IN THE STOMACH. 227 



different substances, and killed them in a certain number of 

 hours afterwards. But the results they obtained are of less 

 interest than those of the experiments of Dr. Beaumont on his 

 patient, St. Martin, and of Dr. Gosse, who had the power of 

 vomiting at will. 



Dr. Beaumont's observations show, that the process of di- 

 gestion in the stomach, during health, takes place so rapidly, 

 that a full meal, consisting of animal and vegetable substances, 

 may nearly all be converted into chyme in about an hour, and 

 the stomach left empty in two hours and a half. The details 

 of two days' experiments will be sufficient examples : 



Exp. 42. April 7th, 8 A.M. St. Martin breakfasted on 

 three hard-boiled eggs, pancakes, and coffee. At half-past 

 eight o'clock, Dr. Beaumont examined the stomach, and found 

 a heterogeneous mixture of the several articles slightly 

 digested At a quarter past ten, no part of the break- 

 fast remained in the stomach. 



Exp. 43. At eleven o'clock the same day, he ate two 

 roasted eggs and three ripe apples. In half an hour they 

 were in an incipient state of digestion ; and a quarter past 

 twelve no vestige of them remained. 



Exp. 44. At two o'clock P.M. the same day, he dined on 

 roasted pig and vegetables. At three o'clock they were half 

 chymified, and at half-past four nothing remained but a very 

 little gastric juice. 



Again, Exp. 46. April 9th. At three o'clock P.M. he 

 dined on boiled dried codfish, potatoes, parsnips, bread, and 

 drawn butter. At half-past three o'clock examined, and took 

 out a portion about half digested ; the potatoes the least so. 

 The fish was broken down into small filaments ; the bread and 

 parsnips were not to be distinguished. At four o'clock, ex- 

 amined another portion. Very few particles of fish remained 

 entire. Some of the few potatoes were distinctly to be seen. 

 At half-past four o'clock, he took out and examined another 

 portion ; all completely chymified. At five o'clock stomach 

 empty. 



Many circumstances besides the nature of the food are apt 

 to influence the process of chymification. Among them are, 

 the quantity of food taken ; the stomach should be fairly filled, 

 not distended : the time that has elapsed since the last meal, 

 which should be at least enough for the stomach to be quite 

 clear of food : the amount of exercise previous and subsequent 

 to the meal, gentle exercise being favorable, overexertion in- 

 jurious to digestion ; the state of mind tranquillity of temper 

 being apparently essential to a quick and due digestion : the 

 bodily health : the state of the weather. But under ordinary 



