284 
EXPERIMENTS ON DIGESTION. 
are of diminished size. The nerves of the stomach are equally 
shortened and more sinuous. The external or peritoneal, and the 
internal or mucous tunics, present almost innumerable minute 
folds, projecting and curved in every direction, and produced by the 
contraction of the muscular coat. 
The Gastric Juice . — In the dog the internal membrane of the 
stomach presents no appearance of moisture, except a few drops 
here and there ; some of them almost as clear as water, and others 
a little clouded, holding suspended some mucous flocculi of a grey- 
ish white colour, extensible between the fingers, and also adhering 
to the coat of the stomach. 
In the stomach of a horse that had not eaten during thirty hours, 
we found about 1200 grains of a pale yellow liquid, a little turbid 
and adhesive, and in which were some white mucous flocculi. The 
stomach of another horse that had fasted during the same period 
contained about 500 grains. The liquid found in the stomachs 
of both the dog and the horse had a peculiar animal odour, and a 
slight saline taste. It scarcely acted on the tincture of turnsol, or 
only produced the lightest shade of red. 
When, after fasting some dogs and horses, we made them swal- 
low several small pebbles, and killed them a little while afterwards, 
we found the coats of the stomach contracted round these foreign 
bodies. If, however, the animals were not killed until some hours 
had elapsed, the stones were no longer found in the stomach, the 
contractile motion of the muscular fibres having propelled them 
into the small intestines, with the exception of a few that occa- 
sionally remained in the stomach of the horse. 
The stomach, mechanically irritated by the pebbles, contained a 
larger quantity of whitish grey fluid, part of it liquid and tran- 
sparent, and part somewhat turbid, ropy, and mucous. Three dogs 
which we had compelled to swallow the pebbles, furnished, each of 
them, from three to five grains of this fluid. The stomach of the 
horse yielded a great quantity of the gastric juice, with a few 
hay-stalks that were not digested. 
The same fluid, abundantly obtained by compelling the animal 
to swallow some pieces of white flint, was very acid, and strongly 
reddened the tincture of turnsol, whether obtained from the dog or 
the horse. If, however, we compelled the dog to swallow pieces of 
calcareous earth or stone, the tincture of turnsol was scarcely red- 
dened, for the free acid of the gastric juice had been partly neutral- 
ized by its combination with the lime. 
It resulted from these and other experiments, that, while the 
animal was living, not only the mucous membrane of the stomachs, 
mechanically irritated by the pebbles, furnished an abundant se- 
cretion of gastric juice, but that fluid had a more decidedly acid 
