464 Prof. Liebig oji the Co)isiitufio?i of 



as well as of the ashes of the cereals and the leguminous plants. 

 There are no carbonated alkalies among the soluble salts of 

 these ashes, but bibasic and tribasic phosphates of the alkalies, 

 phosphate of soda or of potass, or both at the same time in 

 varying properties. We might have supposed that the food 

 in the stomach when in a state of solution would manifest the 

 reaction of those salts which form the constituents of the ashes 

 of the aliments partaken of. Now, in fact, all the bibasic and 

 tribasic phosphated alkalies have an alkaline reaction, and yet 

 nevertheless the reaction of the chyme is acid. 



According to the best authenticated investigations, the acid 

 reaction of the gastric juice is owing to the presence of free 

 hydrochloric acid, and for the origin of this acid we must refer 

 to common salt. 



It is obvious that common salt undergoes decomposition in 

 the organism, and becomes resolved into hydrochloric acid, 

 which we find in a fiee state in the gastric juice, and into soda. 

 This latter substance is, previous to the chyme having assumed 

 the form adapted for its transformation into blood, that is, 

 previous to its being changed into chyle, reconducted into the 

 alimentary canal through the medium of the bile, the only 

 compound of soda which we know with certainty to exist, as 

 such, in the organism. 



When we compare the composition of flesh, or of coagulated 

 albumen, with that of the blood, we find a very considerable 

 difference with regard to the inorganic constituents of these 

 substances. The serum of the blood is miscible with water 

 in all proportions, and has an alkaline reaction ; the muscular 

 fibre is insoluble, and has no alkaline properties. The ashes 

 of blood contain principally alkaline phosphates, whilst the 

 ashes of muscular fibre contain a far larger proportion of 

 phosphate of lime. It is obvious that upon the transformation 

 of the blood into muscular fibre, the greater amount of alka- 

 line phosphates re-enter the circulation, whilst a certain 

 amount of phosphate of lime remains in the organs in a state 

 of chemical combination. When we consider that the insolu- 

 bility of flesh, and of the cellular tissue in their natural state, 

 depends upon the presence of the insoluble phosphate of lime, 

 and that by the removal of the phosphate of lime the power 

 of dissolving in alkaline fluids is restored to or increased in 

 the remaining constituents containing nitrogen and sulphur, 

 the necessity of the presence of free hydrochloric acid in the 

 formation of chyme becomes immediately manifest. No mi- 

 neral acid, and still less no organic acid, such as lactic acid 

 or acetic acid, possesses the power of dissolving boiled meat 



