58 PROCEEDINGS OF THE BRITISH ASSOCIATION. 



for that unfailing secnrity from ajj^e OTor<e?« solution which the stomach appears 

 to enjoy. From the articles swallowed, abrasion of the mucous membrauce may 

 be presumed to have been not unfrequently produced, and ulceration is not of so 

 uncouimou an occurrence ; yet perforation has not been observed as the necessary 

 result. The problem, therefore, as to why the stomach is not susceptible of at- 

 tack during life as it is after death, still remains open for solution; and the view 

 that I have to offer refers the immunity observed to the circulation within the 

 walls of the organ of an alkaline current of blood. It will not be disputed that 

 the presence of acidity is one of the necessary circumstances for the accomplish- 

 ment of gastric digestion. Now, alkalinity ia a constant character of the blood, 

 and, as during life, the walls of the stomach are everywhere permeated by a car- 

 rent of this alkaline blood, we have here an opposing influence, the effect of which 

 would be to destroy, by neutralizing its acidity, the solvent properties of the di- 

 gestive fluid tending to penetrate and act upon the texture of the organ. The 

 blood being stagnant after death, the opposing influence is lost that is offered by 

 the circulating current. Should life happen to be cut short at a period of diges- 

 tion, there is only the neutralizing power of the blood actually contained in the 

 vessels of the stomach, to impede the progress of attack upon the organ itself; and 

 the consequence is, that digestion of its parietes proceeds, as long as the tempera- 

 ture remains favourable for the process, and the solvent power of the digestive 

 liquid is unexhausted. There is, therefore, no want of harmony between the effect 

 that occurs after death and the explanation that refers the protection afforded du- 

 ring life to the neutralizing influence of the circulation. In support of this view I 

 have found, experimentally, that by arresting the flow of blood through the sto- 

 mach during life, the organ is placed in the same condition as it is after death : 

 having lost its protecting influence, digestion of its texture now proceeds. It will 

 be naturally required of me to reconcile the view advanced, with the effect that ia 

 noticed when the living frog's legs and rabbit's ears were introduced through a fis- 

 tulous opening into the digesting stomach. If the circulation, through its neutral- 

 izing power, protect the stomach, why should it not have afforded equal protec- 

 tion to the tissues of the living animals introduced through a fistulous opening 

 into the organ ? According to the proposition offered, the result is involved in a 

 question of degree of power between two opposing influences. And because 

 through degree of vascularity the neutralizing power of the circulation is suflScient 

 to hold in check the solvent action of the gastric juice in the case of the walls of 

 the stomach, it does not follow that it should similarly be sufficient to do so in the 

 ease of the frog's legs and rabbit's ears. With the frog it may be fairly taken that 

 the amount of blood possessed by the animal would be totally inadequate to fur- 

 nish the required means of resistance to the influence of the acidity of a dog's 

 gastric juice. With the rabbit's ears the vascularity is so much less than that of 

 the walls of the stomach that there is nothing incomprehensible in the fact of the 

 one yielding to, and the other resisting the attack. In support of ths position that 

 has been taken, it can be shown by experiment that even with the stomach itsel:^ 

 by increasing the acidity of its contents beyond a certain point, its circulation is 

 no longer adequate to enable it to resist digestion. 



