208 
ON EUPATORIUM PERFOLIATUM. 
tained : this was removed from the receiving vessel and the pro- 
cess continued until three pints more had passed, when the liquid 
came through nearly colorless. The liquid last obtained was 
evaporated to a small bulk, the first pint added and the whole 
evaporated to the consistence of an extract, which weighed 630 
grains, and was reserved for future examination. 
As the liquid which came through after the four pints above- 
mentioned were obtained, although nearly colorless, still possessed 
much bitterness, I deemed it advisable to continue the process, 
supposing that the gum, salts, and other matters readily soluble in 
water, had been dissolved out by the first portions of menstruum, 
and that the bitter principle now being taken up would be much 
more free from impurities. About four pints were thus passed 
through, when the operation was stopped. This was evaporated 
below 212° to about four fluid ounces, and filtered to separate in- 
soluble extractive : the clear liquid was then reduced to a thick 
syrupy consistence, and treated with deodorized alcohol ; the alco- 
holic solution was concentrated, treated with animal charcoal, 
which removed nearly all the color, and submitted to spontaneous 
evaporation, when a resinous looking matter of a brownish yellow 
color separated in globules, but ultimately formed a brittle mass 
amounting to twelve grains, upon the complete evaporation of the 
liquid. This was slightly soluble in water, to which it communi- 
cated a strong bitterness, abundantly soluble in alcohol and soluble 
also in ether. It was dissolved by caustic potassa. 
It was redissolved in alcohol, treated with purified animal char- 
coal, and the solution again left to spontaneous evaporation, 
when the same resinous-looking matter was left as before, pos- 
sessing the peculiar bitter taste of the plant. 
Expt. 2. — The four ounces which had been previously nearly 
exhausted by water, were percolated with alcohol, when an in- 
tense green, bitter solution resulted ; this was evaporated to a 
small bulk, decanted, and the matter adhering to the sides of the 
evaporator, (which seemed to be of a waxy nature,) washed with 
alcohol and added to it. Officinal acetic acid was now added as 
long as chlorophylle precipitated, and the liquid filtered ; the clear 
solution was then evaporated, when, as the alcohol was drawn off*, 
a black tasteless resin was deposited in considerable quantity. 
This resin was soluble in caustic and carbonated alkalies. 
