2/2 DIGESTION. 



out in minute drops, which gradually run together and flow 

 down the walls of the stomach, or soak into the substances 

 introduced. The quantity of this fluid secreted daily has 

 been variously estimated ; but the average for a healthy 

 adult has been assumed to range from ten to twenty pints 

 in the twenty-four hours (Brinton). 



The first accurate analysis of the gastric fluid was 

 made by Dr. Prout : but it does not appear that it was 

 collected in any large quantity, or pure and separate 

 from food, until the time when Dr. 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 external opening was situate two inches 

 below the left mamma, in a line drawn from that part 

 to the spine of the left ilium. The borders of the 

 opening into the stomach, which was of considerable size, 

 had united, in healing, with the margins of the external 

 wound, but the cavity of the stomach was at last sepa- 

 rated from the exterior by a fold of mucous membrane, 

 which projected from the upper and back part of the 

 opening, and closed it like a valve, but could be pushed 

 back with the finger. The introduction of any mechanical 

 irritant, such as the bulb of a thermometer, into the 

 stomach, excited at once the secretion of gastric fluid. 

 This could be drawn off with a caoutchouc tube, and could 

 often be obtained to the extent of nearly an ounce. The 

 introduction of alimentary substances caused a much more 

 rapid and abundant secretion of pure gastric fluid than 

 the presence of other mechanical irritants did. No in- 

 crease of temperature could be detected during the most 

 active secretion; the thermometer introduced into the 

 stomach always stood at 100 Fahr., except during mus- 

 cular exertion, when the temperature of the. stomach, like 



