

CHAP. II.] ARTIFICIAL GASTRIC JUICE. 81 



COMPOSITION OF THE GASTRIC JUICE OF THE DOG, OBTAINED WITH- 

 OUT ADMIXTURE WITH SALIVA (THE MEAN OF TEN ANALYSES BY 

 C. SCHMIDT). 



Water in 1000 parts . . . 973*062 

 Organic matters (including peptones, 



pepsin, mucin) .... 17127 



FreeHCl 3'050 



NaCl . . . . . . 2-507 



KC1 1-125 



NH 4 C1 0-468 



CaCl 2 0-624 



Ca 3 2(P0 4 ) 1-729 



Mg 3 2(P0 4 ) 0-226 



FePO. 0-082 



SECT. 6. ARTIFICIAL GASTRIC JUICE. 



It has been stated that the most striking property of the gastric 

 juice is its power of dissolving and digesting solid proteid bodies, 

 providing the process be carried on at a favourable temperature, 

 that is from 20 40 C. ; it has also been stated that this property 

 depends upon the presence of an enzyme called pepsin and a free 

 acid, neither of these being capable of acting, in its characteristic 

 manner, independently of the other. 



Eberle was the first to shew that the solid mucus which can be 

 scraped from the surface of the mucous membrane of the stomach 

 undergoes solution under the influence of dilute acids. And he 

 thus prepared an artificial gastric juice which possessed the power 

 of digesting suitable substances at a proper temperature 1 . Eberle 

 likewise found that acid in which mucous membrane of the stomach 

 had been digested possessed powers of dissolving proteids. Eberle 

 however fell into the great error of supposing that mucus was the 

 essential proteolytic agent, and actually asserted that with mucus 

 taken from other organs than the stomach, as for example with nasal 

 mucus, digestive liquids could be prepared. 



The observations of Eberle were first repeated by Johannes 

 Miiller, shortly afterwards by J. Muller and his pupil Schwann 2 , and 

 they brought to the work a perspicuity and a scientific acumen which 



1 Eberle, Physiologie der Verdauung nach Versuchen. Wiirzburg, 1834. See at 

 page 156 the following passage: " Magensaft von Thieren gewonnen, bewirkte die 

 Chymification mehrerer Speisen in der Warme auch ausser dem Magen, und nach 

 meinen eigenen Versuchen gelingt endlich noch die Chymification der Nahrungsmittel 

 durch den kiinstlich bereiteten Magensaft in der Warme vollstandig." 



2 J. Miiller u. Th. Schwann, 'Versuche iiber die kiinstliche Verdauung des geron- 

 nenen Eiweisses.' Miiller's Archiv, 1836, p. 66. 



G. 6 



