224 DIGESTION. 



sediment of the color of meat. A similar piece of beef was, at 

 the time of the commencement of this experiment, suspended 

 in the stomach by means of a thread : at the expiration of the 

 first hour it was changed in about the same degree as the meat 

 digested artificially ; but at the end of the second hour, it was 

 completely digested and gone. 



In other experiments, Dr. Beaumont withdrew through the 

 opening of the stomach some of the food which had been taken 

 twenty minutes previously, and which was completely mixed 

 with the gastric juice. He continued the digestion, which had 

 already commenced, by means of artificial heat in a water-bath. 

 In a few hours the food thus treated was completely chymified ; 

 and the artificial seemed in this, as in several other experi- 

 ments, to be exactly similar to, though a little slower than, the 

 natural digestion. 



The apparent identity of the process in- and outside of the 

 stomach thus manifested, while it shows that we may regard 

 digestion as essentially a chemical process, when once the gas- 

 tric fluid is formed, justifies the belief that Dr. Beaumont's 

 other experiments with the digestive fluid may exactly repre- 

 sent the modifications to which, under similar conditions, its 

 action in the stomach would be liable. He found that, if the 

 mixture of food and gastric fluid were exposed to a temperature 

 of 34 F., the process of digestion was completely arrested. In 

 another experiment, a piece of meat which had been macerated 

 in water at a temperature of 100 for several days, till it ac- 

 quired a strong putrid odor, lost, on the addition of some fresh 

 gastric juice, all signs of putrefaction, and soon began to be 

 digested. From other experiments he obtained the data for 

 estimates of the degrees of digestibility of various articles of 

 food, and of the ways in which the digestion is liable to be af- 

 fected, to which reference will again be made. 



When natural gastric juice cannot be obtained, many of 

 these experiments may be performed with an artificial digestive 

 fluid, the action of which, probably, very closely resembles that 

 of the fluid secreted by the stomach. It is made by macerat- 

 ing in water portions of fresh or recently dried mucous mem- 

 brane of the stomach of a pig 1 or other omnivorous animal, 

 or of the fourth stomach of the calf, and adding to the in- 

 fusion a few drops of hydrochloric acid about 3.3 grains to 

 half an ounce of the mixture, according to Schwann. Por- 

 tions of food placed in such fluid, and maintained with it 



1 The best portion of the stomach of the pig for this purpose is that 

 between the cardiac and pyloric orifices ; the cardiac portion appears 

 to furnish the least active digestive fluid. 



