214 
BARK OF QUILL A IA SAPONARIA. 
The nitrate of silver, a light degree of cloudiness; 
The nitrate of baryta, no change ; 
Ammonia augmented the intensity of the color. 
The salts of platina indicated the presence of a small pro- 
portion of potassa. 
The residue of the alcoholic solution from which the pun- 
gent substance (B, which has occupied us,) was precipitated, 
was evaporated by the heat of a salt water bath ; there re- 
mained a clear brown extract (C) possessing a great part of 
the properties of the afore-noticed, but much less pure than 
it, reddening litmus. When dried it was less friable, which, 
doubtless, appertained to a fatty substance. We were con- 
vinced of this, by treating it with sulphuric ether, which left, 
after its entire evaporation, a greasy matter mixed with a 
little chlorophylle. 
A portion of this extract was boiled with an excess of 
caustic magnesia; the precipitate re-dissolved by boiling alco- 
hol, after a slow evaporation, afforded no indication of crystal- 
lization. With respect to the acid which was combined with 
the magnesia, the quantity was so small, that it was impossi- 
ble to determine what it was. 
It has been seen above that the extract obtained from the 
aqueous decoctions, was treated by rectified boiling alcohol.' 
Which only took up a portion of it; the portion untouched (D) 
was of a blackish-brown color, dry, friable, cellular, without 
sensible taste. Cold water allowed to remain in contact with 
it, became strongly colored without appearing to dissolve it 
entirely. This liquid, filtered and evaporated, left as a re- 
siduum, an insipid substance, colored brown, foaming con- 
siderably by agitation in water. Treated with nitric acid, to 
see if it contained gum, no traces of mucic acid were per- 
ceptible. 
Calcined in a crucible, it exhaled an aromatic odor, which 
had some resemblance to that of terebinthinate substances. 
The ash of calcination was a whitish powder, abundant, effer- 
vescing with acids, and which was composed of a considera- 
