182 FLUID EXTRACTS OF RHUBARB AND VALERIAN. 
and nothing but the actual, isolation of the alkaloid will ren- 
der its non-identity with calisaya certain. 
It is said that a lot of the same kind of bark has been ex- 
amined in New York with a similar result, and as the letter 
before quoted states it has been sent to England, we shall 
probably hear of it from abroad. 
Although coming from Guanuco, this bark is not by any 
means to be classed with the Guanuco bark of the books, al- 
though it is analogous to the latter in containing only cin- 
chonia. Pereira states under the head of Huanuco bark, 
that " Ruiz, when appointed to examine a cargo of Huanuco 
bark in 1799, found a bark amongst it which Tafalla has 
designated as " similar to calisaya" — and under the name 
of "light calisaya" Guibourt describes a variety of bark 
which in some of its characters is analagous to the one now 
noticed, but the history of the latter is sufficiently clear to 
render it probable that this is its first appearance in our 
market. The bark described at the commencement of this 
paper, is evidently from the same source in Peru, but was 
not a part of Messrs. R. & D.'s invoice. 
ART. LIV. — ON THE FLUID EXTRACTS OF RHUBARB AND 
VALERIAN. 
By William Procter, Jr. 
The high and justly merited esteem in which Rhubarb is 
held, renders it a fit subject for pharmaceutic research. The 
modified character of most of the liquid preparations of this 
drug, as well as their feebleness, unfits them for many 
cases where it is applicable, and the only resource is the 
