438 
EXPERIMENTS ON DIGESTION. 
We have found the same substances, and in the same state, in 
the reticulum of these animals. 
The aliment contained in the rumen, and in the reticulum, and 
the abundant liquid which mingled with it, was strongly alkaline, 
and effervesced with acids. This was always the case with oxen, 
and also with sheep that w r ere fed on straw or grass. 
The alkaline property of the fluid contained in the paunch has 
been observed by many physiologists. Yicussens remarked that 
the tincture assumed a green colour in the paunch of a goat; and 
Rast saw the syrup of violets change to the same colour in the first 
stomach of a sheep. Carminati found the fluid in the stomach of 
a sheep of a green colour, and an unpleasant smell. It turned the 
syrup of violets green, and had a slightly bitter and saline taste : it 
also strongly effervesced with acids. The testimony of Brugnetelli 
goes to the same point. 
A chemical analysis of the contents of these two stomachs has 
proved the existence of the following substances : — 
1. Free Carbonic Acid. — This is disengaged at the commence- 
ment of the distillation of the fluid in the rumen of oxen and sheep 
fed on grass; and also of that contained in the reticulum of sheep 
that had fed on straw. 
2. Hydro-sulphuric Acid. — This is found both in cattle and 
sheep fed on grass. 
3. Free Acetic Acid has been detected in the paunch of sheep 
fed on oats, and also in that of calves; likewise in the reticulum 
of sheep to which oats and straw had been given. This acid may 
be produced by the decomposition of the alimentary substances, since 
it is only necessary to infuse oats in water in order to produce 
it. Free hydro-chloric acid is not found in the fluids of either 
of the three first stomachs, for, on being burnt, they all yield an 
alkaline carbonate. 
4. Free Butyric Add has been recognised in the sheep that has 
been fed on oats. It was found in a considerable quantity in a 
calf, not entirely, however, from the process of secretion, but in part 
arising from the butyric portion of the milk. 
5. Carbonate of Ammonia. — This is found in the paunch and 
reticulum of cattle; also in that of sheep fed on grass and hay; 
or who had been destroyed after the pancreatic duct was 
opened. The ammonia was super-saturated by carbonic acid. 
This may, perhaps, depend on the bi-carbonate of soda contained 
in the saliva, and, consequently, swallowed with the food, being 
decomposed by an ammoniacal salt, -which probably existed in the 
fluid secreted by the first stomach. It must, however, be attri- 
buted, in part, to the decomposition of the food in these stomachs. 
6. Acetate of Ammonia has been obtained by distilling the 
