262 DIGESTION. 



stance, not coagulable by heat or the acids, called by Leh- 

 inann, caseine-peptone. 



Gelatine is rapidly dissolved in the gastric juice, when it 

 loses the characters by which it is ordinarily recognized, arid 

 no longer forms a jelly on cooling. 1 This substance is much 

 more rapidly disposed of than the tissues from which it is 

 formed ; and the products of its digestion in the gastric juice 

 resemble the substances resulting from the digestion of the 

 albuminoids generally. 



Action on Vegetable Nitrogenized Principles. These 

 principles, of which gluten may be taken as the type, are 

 undoubtedly chiefly, if not entirely, digested in the stomach. 

 Raw gluten is acted upon very much in the same way as 

 fibrin ; and cooked gluten behaves like coagulated albumen. 

 Vegetable articles of food generally contain gluten in greater 

 or less quantity, or principles resembling it, as well as various 

 non-nitrogenized principles, and cellulose. The fact that these 

 articles are not easily attacked in any portion of the aliment- 

 ary canal, unless they have been well comminuted in the 

 mouth, is shown by the passage of grains of corn, beans, etc., 

 in the faeces. When properly prepared by mastication and 

 insalivation, the action of the gastric juice is to disintegrate 

 them, dissolving out the nitrogeiiized principles, freeing the 

 starch and other matters so that they may be more easily 

 acted upon in the intestines, and leaving the hard indigest- 



1 Blondlot studied the comparative action of acidulated water and gastric 

 juice from the dog upon gelatine. He took three vessels, each capable of hold- 

 ing thirty grammes, in each of which he put ten grammes of jelly obtained by 

 boiling one part of isinglass with twenty of water. He then filled the vessels, 

 one with gastric juice, and the two others with water acidulated with phosphoric 

 and with acetic acid. By the action of heat, the jelly was soon dissolved in each 

 of the three vessels. After ten hours, he found that while the specimens of gela- 

 tine in the acidulated water formed a jelly on cooling, so that the vessel could 

 be inverted without any of the substances escaping, the specimen which had been 

 digested in gastric juice retained its fluidity. ( Traite Analytique de la Digestion, 

 Paris, 1843, p. 290.) 



