38 ^ Dr. Pearson on expectorated Matter. 
6 . On boiling the mixtures (5), a great part of the expec- 
torated matter is separated in a curdy form, from a milky 
liquid. 
7. If less than two grains of expectorated matter were 
diffused through five hundred grains of water, no evident 
precipitation was occasioned by tannin ; while with one grain 
of isinglass jelly, or white of egg, or of serum of blood dis- 
solved in five hundred grains of water, there was an evident 
precipitation with this re-agent. 
8. I could arrive at no useful conclusions, for the distinc- 
tion of expectorated matter from other coagulable, or from, 
any gelatinous substances by comparative trials with muriate 
of tin, nitro-muriate of gold, oxymuriate of mercury, acetite 
of ceruss, and acetite of litharge. 
§ V. Agency of acetous Acid. 
1. Twenty ounces of ropy opaque matter, by being shaken 
with ten pints of distilled vinegar, were so broken into a 
fibrous or even vascular form as to exhibit an organized ap- 
pearance, the bulk being reduced to at least one third of the 
ropy matter. By repeated agitation and long digestion, the. 
coagulated masses were broken into smaller pieces, but did 
not appear to be further contracted in bulk, or to dissolve. 
With some parcels of matter, the vinegar preserved its trans- 
parency, with others it became whey-like, the matters being 
deposited in a curdy state. The mucilage-like expectorated 
matter, or this mixed with the other kinds, afforded whey- 
like, or more or less turbid liquids with vinegar. 
2. (a ) The decanted liquid, and the liquid obtained by pres- 
