DIGESTION. 251 



Beaumont was enabled, by a fortunate circumstance, to obtain it from 

 the stomach of a man named St. Martin, in whom there existed, as the 

 result of a gunshot wound, an opening leading directly into the stomach, 

 near the upper extremity of the great curvature, and three inches from 

 the cardiac orifice. The introduction of any mechanical irritant, such 

 as the bulb of a thermometer, into the stomach, through this artificial 

 opening, excited at once the secretion of gastric fluid. This was drawn 

 off, and was often obtained to the extent of nearly an ounce. The in- 

 troduction of alimentary substances caused a much more rapid and 

 abundant secretion than did other mechanical irritants. No increase of 

 temperature could be detected during the most active secretion; the ther- 

 mometer introduced into the stomach always stood at 100 F. (37.8 

 C.) except during muscular exertion, when the temperature of the 

 stomach, like that of other parts of the body, rose one or two degrees 

 higher. 



The chemical composition of human gastric juice has been also in- 

 vestigated by Schmidt. The fluid in this case was obtained by means of 

 an accidental gastric fistula, which existed for several years below the 

 left mammary region of a patient between the cartilages of the ninth and 

 tenth ribs. The mucous membrane was excited to action by the intro- 

 duction of some hard matter, such as dry peas, and the secretion was re- 

 moved by means of an elastic tube. The fluid thus obtained was found 

 to be acid, limpid, odorless, with a mawkish taste with a specific gravity 

 of 1002, or a little more. It contained a few cells, seen with the micro- 

 scope, and some fine granular matter. The analysis of the fluid obtained 

 in this way is given below. The gastric juice of dogs and other animals 

 obtained by the introduction into the stomach of a clean sponge through 

 an artifically made gastric fistula, shows a decided difference in compo- 

 sition, but possibly this is due, at least in part, to admixture with food, 



Chemical Composition of Gastric Juice. 



Dogs. Human. 



Water, 971.17 994.4 



Solids, 28.82 5.39 



Solids- 

 Ferment Pepsin, .... 17.5 3.19 

 Hydrochloric acid (free), . . . 2.7 .2 

 Salts- 

 Calcium, sodium, and potassium, chlor- 

 ides; and calcium, magnesium, and 

 iron, phosphates, . . . . 8.57 2,18 



The quantity of gastric juice secreted daily has been variously esti- 

 mated ; but the average for a healthy adult may be assumed to range 

 from ten to twenty pints in the twenty-four hours. The acidity of the 



