1824.] Nature of the Acid and Saline Matters in Animals. 117 



Article X. 



On the Nature of the Acid and Saline Matters mmUy existing 

 in the Stomachs of Animals. By William Prout, MD. FRS. 



That a free, or at least an unsaturated acid usually exists in 

 the stomachs of animals, and is in some *™" c ™"**™* 

 the important process of d.gestion seems to have been the gene 

 ral opinion of physiologists till the time of Spallanzam. I his 

 flustKs philosopher ^concluded, from ^«gSS£3S 

 ments, that the gastric fluids, when in a perfectly natourf state, 

 are neither acid nor alkaline. Even Spallanzani, however, 

 adJted Sat the contents of the stomach are very generally 

 acid • and this accords not only with my own observation, but 

 with that I believe, of almos/every individual who has made 

 nnv exoeriments on the subject. . . . 



wXe pect to the nature of this acid very various opinions 

 hZ been entertained. Some of the older chemists seem to 

 have considered it as an acid, sui genem: by others it was 

 supposed to be the phosphoric, the acetic, the lactic acid,t i-c 

 Nokss various have been the opinions respecting us origin and 

 use some supposing that it is 'derived from the stomach xtself 

 and is essential to the digestive process; «*£**■* *£ 

 derived from the food, or is a result of fermentation, &c. , n 

 short there seems to be no physiological subject so imperfectly 

 understeod, or concerning which there has been such a variety 



° f ThTobject of the present communication is to show that the 

 acid in question is tL muriatic acid and that the .salts usually 

 met with in the stomach are the alkaline muriates. As to the 

 origin and use of these principles, as well as the occasional 

 appearance of other acids, ft* in the stomach, I reserve what I 

 have to say on these subjects till a future opportunity, and shall 

 merely remark at present, that the facts now adduced seem to 

 be ntlmately connected, not only with the physiology and patho- 

 loVy of "he digestive process, but with other important annual 



fU ]££ ascertained the circumstances above-mentioned in a 

 <reneral manner, and by means which it would be here unneces- 

 sary to detaJ, an attempt was made to contrive some unexcep- 



• From the Philosophical Transactions for 1824, Part I. surpr ised to 



t After I had discovered the principal fact ■J^^J^iTSKS to 

 find how nearly Scopoli had com. U> *e same ~*—± 2ffiK the stomach, 

 the conclusion, as tar as I can ascertain, WMi aml „onia, found in 



but he advanced the opinion that the muriatic aid m U .. »n wrtn , 



such abundance in the stomach of ruiiiinatin K animals, i s sttr "-UJ ^ h 



The only account of Scopoli's experiments I have seen is in Johnson 

 mUtry, i. 183. 



