343 
Dr. Pearson on expectorated Matter. 
saline impregnations, particularly of the muriate of soda, and 
neutralized potash so great, that the exsiccated expectorated 
substance tasted very salt, and presently grew moist, or even 
partially deliquesced ; but the opaque ropy or puriform matter 
afforded a much larger proportion of exsiccated residue, which 
was but slightly salt, and generally only became soft on ex- 
posure to the air. This property of growing moist depends 
upon the potash. 
6. Each of the human fluids, according to my experiments, 
contain neutralized potash ; at least, this is the fact of the blood, 
dropsy fluid, pus of abscesses, and pus secreted without breach 
of surface; the fluid effused by vesicating with cantharides ; 
the urine ; and in course in the very abundant secretion from 
the nose by a catarrh. The alkali being united to oxide of 
animal matter in these fluids, it is easily demonstrable. 
7. Although I think I have discovered many properties by 
which expectorated secretion may be distinguished from ex- 
pectorated pus, I shall not speak of them, on this occasion, 
further than just to observe that the saline impregnation of 
pus, particularly that of potash, and muriate of soda is in very 
much less proportion than in expectorated secretion ; and 
hence it does not become moist after exsiccation, on exposure 
to the air. 
8. It has been, I believe, uniformly asserted, that the circu- 
lating and secreted fluids are impregnated with soda ; that it 
is especially in the matter secreted by the bronchial mem- 
brane. The experiments of others must confirm or disprove 
mine. It seems, however, much more reasonable, that the 
human fluids should be found to contain potash than soda, 
united to some oxide or destructible acid ; because the former 
alkali is daily introduced with the vegetable food, and with the 
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