CEYMIFICATION. 587 



state of decomposition, into lactic acid, has induced physiologists with- 

 out farther inquiry, to assume that lactic acid is produced during di- 

 gestion. He now, however, admits its existence in health, 3 and with 

 Dr. R. D. Thompson and MM. Bernard and Barreswil considers it to be 

 an important agent in the digestive process. With some other che- 

 mists, he denies the existence of free chlorohydric acid in the stomach, 

 and believes, that when it is obtained by the simple distillation of the 

 gastric juice it is formed by the reaction of the lactic and phosphoric 

 acids, which are present in the fluid r on the chlorides ; and recently, 

 Lehmann found, when he experimented on the stomachs of dogs placed 

 in vacuo in such a manner as to cause the vapours from the gastric 

 juice to pass through a tube containing a solution of nitrate of silver, 

 that there was no indication of free chlorohydric acid until the fluid 

 had become so concentrated as to permit the action of the lactic acid 

 on the earthy chlorides. His results would tend to confirm the later 

 conclusions of Liebig, as well as those of MM. Bernard and Barreswil, as 

 to the nature of the acid on the gastric juice of certain animals at least. 2 

 It is proper to remark, however, that neither Prout nor Braconnot 

 could detect the lactic acid in the gastric juice ; and, moreover, it does 

 not appear to be formed in artificial digestion. 3 



The diversity of results obtained by chemical analysis; the difficulty 

 of comprehending how the same fluid can digest substances of such 

 opposite character; and the uncertainty we are in, regarding the 

 organs concerned in its production, have led some physiologists to doubt 

 the existence of any such gastric juice or solvent as that described by 

 Spallanzani. M. Montegre, 4 for example, in the year 1812, pre- 

 sented to the French Institute a series of experiments, from which he 

 concluded, that the gastric juice of Spallanzani is nothing more than 

 saliva, either in a pure state, or changed by the chymifying action of 

 the stomach and become acid. As M. Montegre was able to vomit at 

 pleasure, he obtained the gastric juice, as it had been done by previous 

 experimenters, in this manner, whilst fasting. He found it frothy, 

 slightly viscid, and turbid; depositing^ when at rest, some mucous 

 flakes ; and commonly acid; so much so, indeed, as to irritate the throat, 

 and render the teeth rough. He was desirous of proving, whether this 

 fluid was in any manner inservient to chymification. For this purpose, 

 he began by ejecting as much as possible by vomiting; and, afterwards, 

 swallowed magnesia to neutralize what remained. On eating afterwards, 

 the food did not appear less chymified, nor was it less acid; whence he 

 concluded, that, instead of the fluid being the agent of chymification, it 

 was nothing more than saliva and the mucous secretions of the stomach, 

 changed by the chymifying action of that viscus. To confirm himself 

 in this view, he repeated, with it, Spallanzani's experiments on artificial 

 digestion; making, at the same sime, similar experiments with saliva: 



1 Chemistry of Food, London, 1847. 



2 Archiv. der Phar-macie, c. p. 79, cited in the British and Foreign iledico-Chirurgical 

 Review, p. 261, Jan., 1849. 



3 A full account of the various views in regard to the gastric acid is given by Frerichs> 

 Art. Verdauung, Wagner's Handworterbuch der Physiologic, Slste Lieferung, s. 780, Braun- 

 schweig, 1849; and Berard, Cours de Physiologic, lie Livraison, p. 97, Paris, 1849. 



4 Exper. sur la Digestion, p. 20, Paris, 1824. 



