34,0 Dr. Pearson on expectorated Matter. 
and a little water. Several grains were in this way united, with- 
out any effect being produced by the compound on turmeric 
paper. More alkali was added till the compound barely mani- 
fested the existence of alkali to the test just mentioned. It was 
then digested in spirit of wine, to which it imparted a deep 
brown colour, and the tincture being distilled, it afforded a dry 
extract, which grew moist on exposure to the air, but scarcely 
affected turmeric paper. On incineration, however, the alkali 
was denuded, and fusion was produced easily. 
An equal portion of the animal oxide, of the same parcel as 
in the last experiment, was digested in spirit of wine, in the 
same circumstances as this oxide united to potash. It imparted 
no colour to the spirit, and the ext ract obtained was in smaller 
quantity, than in the preceding experiment. Being evaporated 
to dryness, the residue did not grow moist, but it became a 
little soft on exposure to the air. Being exposed to fire, it 
left an inconsiderable proportion of infusible residue, with 
barely traces of alkali and muriate. 
2. To determine, by a more satisfactory experiment than 
a preceding one, whether or not acid was united to the potash 
and evaporable, ten ounces of watery liquid, which separates 
from the curd on boiling expectorated matter, were evapo- 
rated to the consistence of a thin extract. This matter indi- 
cated neither acid nor alkali in a disengaged state, but it was 
ascertained to contain a large proportion of potash combined ; 
and an acid smell was perceived on heating it with phosphoric 
or tartaric acid. Ten drops of liquid phosphoric acid were 
mixed with four hundred grains of this extract-like matter, 
and at a low temperature it was subjected to distillation to 
become almost a dry substance, but no acid could be detected 
