160 LACTIC ACID THE NORMAL ACID OF THE STOMACH. 
acid, or upon the acid biphosphate oflime. The latter theory, 
advanced by Blondlot, has been disproved by Dumas, 
Bernard and Melsens, who have shown, that not only the 
carbonate, but the basic phosphate of lime, are soluble in 
gastric juice, as are also zinc and iron, with the evolution of 
hydrogen gas, — properties which a solution of acid phosphate 
of lime does not possess.* * * § 
“The analysis of the fluid obtained from St. Martin by 
Dr. Beaumont in 1833-4, and submitted to Prof. Dunglison, 
then of the University of Virginia, showed, as the latter states, 
the presence of e free muriatic and acetic acids, phosphates 
and muriates, with bases of potassa, soda, magnesia, and lime, 
and an animal matter, soluble in cold water but insoluble in 
hot. 5 Dr. Dunglison further states, f we distilled the gastric 
fluid, when the free acid passed over, the salts and animal 
matter remaining in the retort. The quantity of chloride of 
silver thrown down was astonishing/*!* 
“Previously to this analysis, in 1824, Dr. Prout had made 
the same assertion as to the presence of hydrochloric acid, 
based upon the examination pf the contents of the stomachs 
of rabbits killed while digesting; and Braconnot, in 1835, 
subsequently to Dunglison, states that he obtained evidences 
of free hydrochloric acid in gastric juice obtained by sponging 
the stomachs of animals.J 
“More recently, Bernard and Barreswill, Pelous and 
Thompson, have been led to believe, from their own experi- 
mental researches, that lactic acid is the agent upon which 
the characteristic reaction of the gastric juice depends, and 
attribute the presence of hydrochloric acid in the free state to 
the decomposition of the alkaline chlorides by the lactic acid 
at a high heat. Hence, supposing lactic acid to be present 
in the fluid of digestion with the chloride of sodium, the fluid 
which passes over by distillation will, at first , be destitute of 
hydrochloric acid ; but as the liquid becomes more concen- 
trated, and the temperature rises, hydrochloric acid will pass 
over.§ Lehmann denies the power of hydrochloric acid to 
decompose the chloride of sodium, but asserts that chloride 
of calcium is decomposed by lactic acid, even in vacuo ; and 
that hence it is not surprising that pure gastric juice should 
develop vapours in vacuo , which, when passed into a solution 
of nitrate of silver, should form chloride of silver. || 
* ‘Pliys. Chem., 5 by C. G. Lehman. 
f ‘Experiments and Observations on the Gastric Juice/ by Win. Beau- 
mont, M.D., Surgeon U. S. Army. 
% ‘ Annales de Chimie, 5 t. 59, p. 348. 
§ Carpenter’s ‘Human Physiology, 5 Amer. Edit., p. 109. 
|| ‘Pliys. Cliem., 5 vol. i, p. 93. 
