[ 4* ]
compact, and of a darker colour : it is very brittle and re-
finous. The innermoft layer is more woody and fibrous,
and o f a brighter red. In powdering this Bark, the middle
layer, which feems to contain the greateft proportion
of refinous matter, does not break fo readily as the reft; a
circumftance to be attended to, left the moft active part
lhould be left out of the fine powder. This red Bark to
the tafte difcovers all the peculiar flavour of the Peruvian
Bark, but much ftronger than the common officinal fort.
An infufion in cold water is intenfely bitter, more fo than
the ftrongeft decodtion of common Bark. Its aftringency
is in an equal degree-greater than that of the infufion of
common Bark, as is fhewn by the addition of martial vitriol.
The fpirituous tindlure o f the red Bark is alfo pro-
portionably ftronger than that of the pale. The quantity
of matter extracted by rectified fpirit from the powder
o f the former was to that from the latter as 3 to a in one
experiment, and as 229 to 130 in another; and yet on infilling
the two refiduums of the firft experiment in boiling
water, that of the red Bark gave a liquor confiderably bitter,
and which ftruck a black with martial vitriol; while
that yielded by the other, was nearly taftelefs and void of
aftringency*.”
Refpedting the medicinal properties we have feveral
refpedlable authorities, ffiewing, that as the red Bark pof-
fefles the fame virtues with the common, in amuch higher
* Lewis, 1. c.
degree,
degree #, fb it has been found o f more efficacy in the cure
of intermittents : and hence it is thought to be that which,
according to Arrot, the Spaniards called Cafcarilla colora-
da, and was probably the kind originally brought to Europe,
and which proved fo fuccefsful in the hands of
Sydenham, Morton, and Lifter ; for it appears from the
teftimony of the oldeft practitioners, that the Bark firft
employed here was of a much deeper colour than the
common Bark f . The red Bark was firft imagined by Dr.
Saunders J to be that o f the trunk of full grown trees, the
branches or young trees of which yield the pale or common
Bark : but this opinion the Doctor feems afterwards
to have abandoned ; for in the third edition of his pamphlet
on this fubject he fays, * that he has lately feen fome
exceedingly good red Bark imported by a Spaniffi merchant,
a confiderable part of which was as fmall as the
quilled Bark in common ufe, &c. It was extremely refinous,
and gave evident proofs' of its being the quill of the
larger red Bark which was in the fame cheft.” If the pale
and red Bark were really the produce of the fame fpecies
of Cinchona, the latter differing from the former only
by acquiring greater maturity, we ffiould find the deep-
nefs o f the colour of the pale Bark to correfpond propor-
tionably with its thicknefs or the fize of the quill, which
is certainly not the cafe. The Cinchona caribæa is defcribed
* Irving’s and Skeete’s Experiments»
f Baker, Med. Tranf. vol. iii. p. 161.
t Obfervations on the fuperior efficacy of the red Peruvian Bark in the cure
of fevers.
F 2 and