Dr. Pearson on expectorated Matter. 333 
of animal matter for three times, but then no saline matter 
was afforded, but merely animal matter. The residues of the 
evaporated tinctures of the subsequent digestions did not, like 
the first, grow moist, but only softer ; and the oxide of ani- 
mal matter from each of them was no longer coagulable, 
although afforded by dissolution of coagulated matter. It ap- 
peared that the animal oxide was of one kind only, and that 
the whole of it might be dissolved in alcohol, and thereby 
become uncoagulable, and more easily dissoluble in every 
kind of menstruum. 
3. If a large proportion, namely, two parts of expectorated 
matter be mixed with two parts of rectified spirit of wine, the 
matter is in great part, at least, coagulated, but the spirit is 
rendered milky. The same is true with regard to other men- 
strua. The reason is obvious. The coagulation is produced 
by the separation of water from the animal oxide of the 
expectorated matter, by the attraction of the alcohol, or of 
acetous acid for the water; but if there is not a due propor- 
tion of spirit or acid, the oxide of animal matter retains so 
much of the water, as to render the liquid milky. A person 
accustomed to these experiments may determine pretty ex- 
actly by means of them, the proportion of water in the ex- 
pectorated matter, it being directly as the quantity of spirit 
or acid requisite to produce entire coagulation in a clear liquid; 
and the proportion of coagulable animal oxide is, within cer- 
tain limits, inversely as the quantity of spirit requisite for 
coagulation. 
4. Sulphuric ether, being in many properties analogous to 
alcohol of wine, I digested three hundred grains of exsiccated 
matter of the third kind, page 317, in four ounces measure of 
MDCCCIX-. X x 
