THE GASTRIC JUICE. 529 



and ferrocyanide of potassium into the blood of a living animal, pro- 

 duces no blue color in the blood, tissues, or secretions generally, nor 

 even in the gastric glands, yet the surface of the mucous membrane of 

 the stomach is stained blue. Other parts of the body, moreover, be- 

 come blue on the application of an acid. This experiment, therefore, 

 also favors the supposition that the acid of the gastric juice is formed 

 near, or at, the surface. It is uncertain whether the separation of the 

 hydrochloric acid, is a direct result of an act of secretion by secreting 

 cells, or whether it is a secondary product of a decomposition, induced 

 by the action of some other intermediately formed free organic acid. 

 The quantity of solid matter in the gastric juice, and the relative 

 amount of organic and saline constituents, diifer in different animals. 

 It is universally acid, but the nature of the acid, as well as that of the 

 organic peptic agent, may vary in certain cases, according to the spe- 

 cies, age, and diet of the animal. When the stomach is at rest, its 

 mucous secretion is neutral or alkaline, semi-opaque, and more viscid 

 than the gastric juice. 



[In 1856 an opportunity was presented the editor of examining and 

 experimenting upon Alexis St. Martin, the Canadian, with a fistulous 

 orifice in his stomach, the result of an accidental gunshot wound re- 

 ceived when quite a lad. 



Several questions relating to the physiological action of the stomach 

 may be regarded as still unsettled ; among these is that relating to the 

 nature of the acid contained in the gastric juice, and the influence of 

 this secretion upon the various alimentary principles as classified by 

 Prout, viz., saccharine, oleaginous, and albuminous food. 



The analyses, conducted by the careful hand of my colleague, Prof. 

 R. E. Rogers, were made upon the fluids obtained from the stomach 

 while digestion was in progress, for that which was drawn from the 

 stomach while fasting was found to be putrescent. In every instance, 

 and with all kinds of food employed, the reaction of the fluid of diges- 

 tion was acid, while that of the empty stomach (as shown by the intro- 

 duction of test papers through the fistulous orifice), and of the fluid 

 obtained by mechanical irritation, was as distinctly neutral. The tem- 

 perature of the stomach, while digestion was in progress, was about 

 100 to 101 Fahr., when empty about 98 to 99. 



The fluid for examination was obtained by placing the man upon his 

 right side, and gently introducing a large- sized gum-elastic catheter or 

 a small glass speculum. He was then allowed to turn himself towards 

 the opposite side, when the contents of the stomach would readily flow 

 out. In no instance was food allowed to remain in the stomach longer 

 than two hours. The mucous membrane of the empty stomach pre- 

 sented a pale pink color, as described by Beaumont, with the surface 

 lubricated by mucus: when digesting, its color was deepened, and the 

 peristaltic motion could be distinctly seen. During all the experiments 

 St. Martin retained his usual good health, was in excellent spirits, and 

 took his food with appetite. 



All observers, in whatever way they obtained gastric juice, agree on 

 one point, the existence of an acid reaction of the fluid of digestion ; 



34 



