164 LACTIC ACID THE NORMAL ACID OF THE STOMACH. 
acid now produced no precipitate. (See Lehmann’s 6 Phys. 
Chem.,’ p. 93, vol. i.) 
“It thus became a demonstration that the strong acid 
reaction of these gastric fluids was not due to the presence of 
free hydrochloric acid. It seems equally clear that it was an 
organic acid, from the fact that it was destroyed by heat, as 
in Experiment 5 ; and almost certain that it was lactic. To 
decide this doubt, a portion of the distillate, and another of 
the residue in the retort, were tested with zinc, as recom- 
mended by Lehmann Phys. Chem./ p. 92, vol. i), with the 
effect of producing the characteristic crystals of lactate of zinc. 
“ It will be remembered that in Experiments 4 and 8 a faint 
evidence of the presence of hydrochloric in the distillate was 
manifested by the reaction w r ith nitrate of silver. It will also 
be remembered, that Bernard and Barreswill assert that this 
hydrochloric acid is due to the decomposition of the alkaline 
chlorides at a high heat. To ascertain this, the following 
experiment was performed : 
“Experiment 9- — Lactic acid was mixed with chloride of 
sodium, and the two were heated in a retort. The distillate 
gave the faintest possible trace of opalescence when treated 
with nitrate of silver. This evidence can scarcely be relied 
upon, for the solution above described requires so high a 
temperature to produce ebullition, that it was difficult to 
prevent a spurious distillation of the chloride of sodium along 
with the vapour, and from this, it is believed, arose the 
opalescence in the reaction between the distillate and nitrate 
of silver. If lactic acid can decompose the chloride of sodium, 
it can only be in very small amount ; chloride of calcium , as 
Lehmann has shown, can be decomposed by lactic acid, and 
if this be present in gastric juice with lactic acid, we may 
have hydrochloric acid developed by distillation. 
“ May 8th. — A meal of roast beef, with a small portion of salt 
as a condiment, was given to St. Martin at 2 p.m. At 3J o’clock 
of the same afternoon the contents of the stomach were re- 
moved. The fluid w r as viscid, inodorous, presented a flocculent 
deposit, and a marked acid reaction; sp.gr. 1008. The micro- 
scope revealed numerous epithelial cells from the mucous 
membrane of the mouth, downwards as far as the stomach, 
mucous corpuscles, amorphous granular matter, oil globules 
in great abundance, and transversely striated muscular fibres, 
in some of which the sarcolemma was softened and ruptured, 
and the sarcous elements just liberated. 
“The gastric fluid was carried through the same series of 
experiments as those to which the product of bread digestion 
was subjected to, and with a like result. The distillate w^as 
