96 THE WORK OF THE DIGESTIVE GLANDS. 



prevents the stimulating properties of the water. These facts are worthy 

 of serious consideration, both on account of their clinical interest as 

 well as on physiological grounds. We will, however, return to them 

 later. 



Next, it appeared of special interest to study the effects of the 

 so-called food-stuffs viz., the carbohydrates, the fats, and the proteid 

 bodies. It was to be expected, from a priori reasons, that if the gastric 

 juice were specially adapted to act on the proteids, these substances 

 would also prove to be chemical stimuli of the mucous membrane of the 

 stomach. How astonished were we then to find, that when fluid egg- 

 white was introduced into the stomach of our dog, either pure or diluted 

 with an equal volume of water, we obtained no greater secretion than a 

 similar volume of water had caused. This seemed to us so peculiar, 

 that the experiment with egg-white was repeated till no doubt whatever 

 of its reliability could exist. The result was also corroborated in the 

 laboratory by Professor Rjasanzeff at a later period, when investigating 

 the way in which egg-white, after introduction into the alimentary canal, 

 is able to influence the output of nitrogen in the urine, although it 

 calls forth no digestive work. This is altogether a wholly unexpected 

 fact. It would be difficult to find either a physiologist or a physician 

 who, if asked what happens to egg-albumen when introduced into the 

 stomach by means of the sound, would not reply, " Naturally, it is 

 digested by the secretion of gastric juice, which it sets up." 



A positive result from chemical excitation of the gastric mucous 

 membrane was, however, obtained when we injected a peptone product 

 manufactured by the firm of Chapoteau. The experiments with this 

 preparation always gave a marked secretory effect every time they were 

 repeated. Other experiments, however, in which a preparation obtained 

 from Stoll and Schmidt in St. Petersburg was employed, furnished 

 wholly negative results that is to say, the peptone solutions acted 

 merely as water acts. Dr. Dzierzgowski analysed both preparations for 

 a special purpose in Professor V. Nencki's laboratory, and kindly com- 

 municated to us, that the peptone of Chapoteau contained as much as 

 50 per cent, of pure peptone, while that of Stoll and Schmidt consisted 

 almost entirely of albumose, and only to the smallest extent of peptone. 



A comparison of these chemical results with the physiological 

 effects, led myself and Dr. Chigin to infer that peptone must be the 

 chemical stimulant of the neuro-glandular apparatus of the stomach 

 which we sought. This belief, on further investigation, proved, how- 

 ever, to be erroneous ; for neither pure peptone nor the products 

 obtained by the action of strong and pure gastric juice on raw fibrin, 

 gave constant effects. On the other hand, meat broth, meat juice, and 

 solutions of meat extract proved to be constant and active exciters of 



