EXPERIMENTS ON DIGESTION. 175 
cent, of solid matter, and that prevails most in the saliva of the 
dog. 
2. The solid portions consist of — 
A. Salivary matter. 
B. Osmazome. 
C. Mucus, which appears to be partly dissolved in the fluid by 
means of an alkaline carbonate, and which gives to it its flaky 
appearance. 
D. A very small portion of albumen. 
E. In the saliva of the human being, a small portion of fatty 
matter, containing phosphorus. 
F. The soluble salts in the fluid are — 
a. An alkaline acetate, the presence of which is only demon- 
strated by incineration, and not by the extraction of an acetic acid. 
b. An alkaline carbonate, which gives to the saliva the property 
of turning the tincture of turnsol blue, and, in the sheep, causing 
it to effervesce with acids. It is in the state of a bi-carbonate. 
The saliva of the sheep contains the greatest portion of it ; it is 
less in that of the dog, and least of all in that of the human being. 
c. An alkaline phosphate, greater in quantity in man than in 
the sheep or the dog. 
d. An alkaline sulphate, existing only in minute quantities in 
either of them. 
e. An alkaline chloruret, in great abundance in all three of them. 
f An alkaline cyanuret, in greatest quantity in the saliva of the 
human being, in a smaller degree in that of the sheep, and not 
found at all in that of the dog. The alkali in the saliva of the 
human being is almost entirely potash. That in the dog and the 
sheep consists of soda, with very little potash. 
G. The solid salts in the fluid portion of the saliva are — 
a. A considerable quantity of phosphate of lime. 
b. Less of carbonate of lime. 
c. A small quantity of magnesia in that of man, but which has 
not been found in either of the others. 
Birds. 
The glands which secrete the saliva in birds are far less deve- 
loped than in the mammalia. Two small glands are found under 
the tongue in the angle formed by the union of the two branches 
of the lower jaw. In their situation they nearly correspond with 
the sublingual glands of the mammalia, but they very much differ 
from them in their structure. They are composed of small hollow 
globules, with numerous minute openings, resembling compound 
muciparous glands. Other glands of the same kind are found in 
