58 REPORT— 1839. 



On the Proofs of the existence of free Muriatic Acid in the Stomach 

 during Digestion. By Dr. R. D. Thomson. 



The object of this communication was, to offer some experiments 

 which would appear to call in question the principle upon which those 

 were founded, from which Dr. Prout, and Messrs Tiedeman and Gmelin 

 came to the conclusion, that free muriatic acid exists in the stomach 

 of animals during digestion. To show that this point should not be 

 conceded, Dr. Thomson stated the following facts : Dr. Thomson 

 was first led to doubt the statement that free muriatic acid exists in 

 the stomach, from the circumstance of finding muriatic acid not so 

 efficacious as sulphuric in the treatment of alkaline indigestion. He 

 was then induced to examine the nature of the experiments of Dr. 

 Prout, and has arrived at results which seem to render them question- 

 able, if not to disprove the grounds upon which Dr. Prout arrived at 

 the conclusion, that free muriatic acid exists in the stomach of animals. 

 Having obtained a quantity of fluid from the stomach, he evaporated 

 it, and, according to the process of Prout, ignited the residue. On 

 dissolving the residue in water, and evaporating spontaneously, fine 

 crystals of carbonate of soda were obtained along with numerous 

 crystals of common salt. These could proceed only from one of two 

 sources, viz. the decomposition of lactate of soda, should any have 

 existed in the fluid, or from the decomposition of common salt. The 

 author was inclined to attribute it to the latter source rather than to 

 the former, in consequence of the very considerable number of crystals. 

 Pie had further found, in pursuing his experiments, and in accordance 

 with this result, that certain organic substances possessed the property 

 of decomposing common salt ; when tartaric acid and common salt are 

 heated together, copious fumes of muriatic acid are given out. The 

 same phenomenon occurs with citric and oxalic acids : sago also would 

 appear to produce some decomposition, and also saliva ; but the latter 

 experiment requires so much delicacy, that Dr. Thomson could not 

 affirm the fact with certainty. 



On the Elementary Constitution of Organic Substances. 

 By the Rev. T. Exley, A.M. 

 Referring to the deductions from his hypothesis of the atomic con- 

 stitution of matter, which regard the union of atoms, and groups of 

 atoms, the author represented graphically, as well as by symbols, the 

 atomic arrangements in several substances which undergo remarkable 

 chemical changes. For example, in organic compounds, of many of 

 which water and olefiant gas are the true sources ; as, 



1. Pyroxylic spirit H (H^ O) C H 



2. Alcohol H^ C (H, O) C H^ 



3. Ether H, C^ (H„ O) C^ H^ 



4. Valerianic acid Hg C^ (C^ O3 H^) C4 H g 



5. Ethal H16 Cs (H, O) Cg H.^ 



6. Sulpho-acetic acid H32 C,5 (SO3 H.^ O^ Cje Hgc 



7. Stearine Hg^ €33 (C3 Hj CO) C32 Hg4. 



