214 
MEDICINAL PLANTS. 
these barks so much resemole each other, that it is not easy 
to distinguish them at first sight. But before we examine the 
question, whether we shall one day discover, in the real 
cinchona, in the cuspa of Cumana, the Cortex Angostura, 
the Indian swietenia, the willows of Europe, the berries of 
the coffee-tree and uvaria, a matter uniformly diffused, and 
exhibiting (like starch, caoutchouc, and camphor) the same 
chemical properties in different plants, we may ask whether, 
in the present state of physiology and medicine, a febrifuge 
principle ought to be admitted. Is it not probable, that 
the particular derangement in the organization, known under 
the vague name of the febrile state, and in which both the 
vascular and the nervous systems are at the same time 
attacked, yields to remedies which do not operate by the 
vame principle, by the same mode of action on the same 
organs, by the same play of chemical and electrical attrac- 
tions ? "We shall here confine ourselves to this observation, 
that, in the species of the genus cinchona, the antifebrile 
virtues do not appear to belong to the tannin (which is onlv 
accidentally mingled in them), or to the cinchonate of lime ; 
but in a resiniform matter, soluble both by alcohol and bv 
water, and which, it is believed, is composed of two prin- 
ciples, the cinchonic bitter and the cinehonic red.* May it 
then be admitted, that this resiniform matter, which pos- 
sesses different degrees of energy according to the combina- 
tions by which it is modified, is 'found in all febrifuge sub- 
stances? Those by which the sulphate of iron is precipitated 
of a green colour, like the real cinchona, the bark of the white 
willow, and the horned perisperm of the coffee-tree, do not 
on this account denote identity of chemical composition ;f 
and that identity might even exist, without our concluding 
that the medical virtues were analogous. We see that 
that the roots of the real cinchona are not employed in pharmacy. Che- 
inieal researches are yet wanting upon the very powerful bitters contained 
in the roots of the Zanthoriza apiifolia, anti the Acttea racemosa : the 
latter have sometimes been employed with success as a remedy against the 
epidemic yellow fever in New York. 
* In French, “ I’amer et le rouge cinclionlques.” 
_ f The cuspare bark (Cort. Angosturte) yields with iron a yellow preci- 
pitate ; yet it is employed on the banks of" the Orinoco, and particularly 
at the town of St. Thomas of Angostura, a3 an excellent cinchona ; and 
on the other hand, tho bark of the common cherry tree, crhich ha: 
