322 Dr. Pearson on expectorated Matter , 
§ II. Agency chiefly of Caloric. 
i. No effect of importance is produced by this agent, until 
the temperature of the expectorated matters is raised to about 
150° of Fahrenheit’s thermometer: then the state of aggre- 
gation is evidently altered, the viscidity of each of them being 
diminished. At about 155 0 , coagulation begins to be quite evi- 
dent in the first, third, fourth, and fifth kinds of matter — -that 
is, curdy masses of various magnitudes appear in a milk- 
like, or whitish liquid. On elevating the temperature to 160° 
or 170°, a large proportion of curd is formed ; but the 
proportion of the curdy matter to the liquid is very different 
in different specimens, The viscid texture, or tenacity of the 
expectorated matters, is by this treatment destroyed. The 
milky liquid decanted, after standing ten or twelve hours, 
affords, on evaporation to dryness, about three to four grains 
of residue from each 100 grains. 
This liquid passes very slowly through the paper filter. 
The filtrated liquor affords scarcely more than one per cent, 
on evaporation to dryness. By repeatedly boiling in successive 
portions of water, the whole, as far as I could judge, of a 
given quantity of the curd might be diffused to form a whitish 
liquid ; which on evaporation to dryness appeared to afford a 
residue of the same kind (except in containing a smaller pro- 
portion of saline substances ) , as the milky liquid which was 
separated from the curd on the coagulation of the expectorated 
matter. 
The second kind, called mucilage-like transpare?it matter , 
does not afford curdy masses at the temperatures abovemen- 
tioned ; but its viscid texture is destroyed, and it becomes a 
whey-like, or somewhat milky liquid ; and, on examination 
