236 DIGESTION. 



was not mentioned by the authors just cited as essential to 

 the solvent action of the gastric juice ; but experiments on 

 artificial digestive fluids by Eberle, Schwann and Muller, 

 Wasmann, and others, demonstrated that acidulated infu- 

 sions of the mucous membrane of the stomach, possessing all 

 the physiological properties of the gastric juice, contained 

 an organic matter, first isolated by Wasmann, on which the 

 solvent powers of these acid fluids seemed to depend. The 

 experiments of Schwann and Muller upon the action of arti- 

 ficial digestive fluids are very interesting, and corrected the 

 mistake made by Eberle, who supposed that an organic sub- 

 stance, with the same properties as that made from the stom- 

 ach, could be extracted from any of the mucous membranes. 1 

 Mialhe, who has obtained this substance in great purity by 

 the process recommended by Yogel, describes the following 

 properties as characteristic of the organic matter in artificial 

 gastric juice. Dried in thin slices on a plate of glass, it is in 

 the form of small, grayish, translucent scales, with a faint 

 and peculiar odor, and a feebly bitter and nauseous taste. 

 It is soluble in water and in a weak alcoholic mixture, but is 

 insoluble in absolute alcohol. A solution of it is rendered 

 somewhat turbid by a temperature of 212 Fahr., but it is 

 not coagulated, though it loses its specific properties. It is 

 not affected by acids, but is precipitated by tannin, creosote, 

 and a great number of the metallic salts. 2 This substance 

 dissolved in water slightly acidulated possesses, in a verv 

 marked degree, the peculiar solvent properties of the gastric 

 juice ; but it has been found by Payen and Mialhe not to be 

 so active as the principle extracted from the gastric juice it- 

 self, which is described by Payen under the name of gas- 

 terase. 3 In the abattoirs of Paris, Mialhe collected from the 



1 MUELLER, Manuel de Physiologic, traduit par Jourdan, Paris, 1851, toine i., 

 p. 465. 



8 MIA.LHE, Chimie appliquee d la Physiologic et d la Therapeutiqne, Paris, 1856, 

 p. 39. 



3 PA YEN, Note sur le Principe actifdu Sue Gastriquc. Comptes Rendus, Par- 

 is, 1843, tome xvii., p. 654 et seq. 



