520 
EXPERIMENTS ON DIGESTION. 
of spelt. These grains were quite softened, and, on pressing them, 
a white milky fluid escaped. 
In a sheep that had been fed on grass, the stomach was filled with 
a brown-yellow fluid, in which floated some small flocculent fibres. 
The stomach of another that had been fed on hay contained a 
thicker fluid, composed of small fibres, and a white-brown milky 
fluid. The abomasum of a third, that had been fed on oats, was 
filled with a liquid bouillie exhaling a pungent and disagreeable 
odour. This bouillie was composed of a farinaceous pulverized 
sediment, some small masses of oats, and a yellowish-white fluid 
having the consistence of milk. The fourth stomach of another 
sheep that had been fed on oats, and that died after the pancreatic 
juice had been collected from it, contained a yellow-brown liquid of 
the consistence of milk, and which deposited a flocculent sediment. 
The substances which we found in the abomasum of all the ani- 
mals that we examined contained a free acid, and deeply reddened 
the tincture of turnsole. They were alkaline only in the sheep that 
died after our experiments upon it, and which we attributed to the 
painful operation to which we had subjected it having diminished 
the influence of the nervous system on the gastric juice. The 
acidity of the fluid contained in the abomasum has been observed 
by the majority of experimentalists. Bourdelin and Duverney 
had, long ago, remarked that the tincture of turnsole was reddened 
by it. . 
If this stomach is washed it still possesses the same property. 
If some chymists have found the gastric juice of ruminants at one 
time acid and at another alkaline, it is because they have not been 
sufficiently careful in collecting the contents of the different sto- 
machs, and because they had not dreamed that these liquids might 
present different characters in the different pouches in which they 
were enclosed. The acidity of the fluid contained in the fourth 
stomach is also proved from its being the agent by means of which 
the milk received into the stomach is coagulated. 
We have found the following substances in the abomasum of the 
ruminants which we have opened : 
1. Acetic Acid . — This existed in a considerable quantity in the 
fluid expressed or filtrated from the abomasum of some calves, and 
oxen, and three sheep fed on grass, hay, and oats. 
2. Hydrochloric Acid in a small quantity in sheep fed on 
grass and on straw. As the fluid in the fourth stomach of calves 
and oxen yields an alkaline carbonate by incineration, it is not pos- 
sible that it should contain any free hydrochloric acid. 
3. Butyric Acid in calves, oxen, and sheep fed on hay. 
4. Carbonate of Ammonia . — This was found only in the aboma- 
