PATHOLOGY OF GASTRIC SECRETION. 169 



of the stomach been here revealed a function of which we could form 

 no adequate conception in the normal course of aft'airs ? By virtue of 

 its wonderful power of secretion, a large quantity of mucous fluid is 

 poured out which dilutes the noxious substance, or forms chemical combi- 

 nations with it, and drives it away at the same time from the stomach 

 wall. The surface epithelium thus wards off the danger which threatens 

 the more important elements of the mucous membrane beneath. 



That this explanation is correct is also shown by the fact that the 

 peptic glands remain absolutely at rest, in striking contrast to the 

 extreme activity of the surface epithelium. 



The chemical substances mentioned stimulate therefore the one 

 kind of epithelium only, leaving the other unaffected. A similar 

 differentiation of stimulating effect we have already seen in the case of 

 flesh, which when brought into the stomach excites only the cells of the 

 peptic glands, leaving those of the surface quiescent. We have here 

 before us, it appears to me, an unusually weighty fact namely, that 

 extraordinary stimuli which come in as pathogenic agencies, are at the 

 same time specific excitants of the protective mechanisms of the organism 

 namely, of those forms of apparatus which are adapted to overcome 

 the disease producing effects. I believe that this applies to all diseases, 

 and that it gives a general indication of the adaptive mechanisms of the 

 animal body, by which it is enabled to encounter pathogenic influences. 

 Indeed, the intricate progress of normal life, with all its power of 

 adaptation, is dependent upon the specific excitability of this or that 

 apparatus. 



Naturally the effects of the substances named, when of a certain 

 strength, may also extend to the deeper layers of the mucous mem- 

 brane, notwithstanding the energetic protection of the epithelium. We 

 then see an altered form of activity in the peptic glands, which in its 

 details may vary greatly, according to the nature of the causal con- 

 dition, but which for the most part assumes a phasic character. In this 

 way we succeeded in establishing different pathological conditions of the 

 peptic glands, and, at the same time, furnished a rich contribution to 

 the physiological characteristics of the gland cells. We have already 

 a considerable store of remarkable observations, but I wish only to call 

 your attention to the following. By the application of a 10 per cent, 

 solution of nitrate of silver we have been able to produce a condition of 

 asthenia, that is, of irritable debility of the peptic glands. (Experiments 

 of Dr. J. C. Sawriew.} In the following two columns are given 

 the hourly quantities of juice, secreted by the isolated miniature 

 stomach, before and during the pathological condition experimentally 

 provoked. The animal was fed each time on the same quantity 

 (150 grms.) of flesh : 



