55° 
dering this bark, the middle layer which feerns to contain the greater!: 
proportion of refmous matter, does not break fo readily as the reft ; 
a circumftance to be attended to, left the moft active part mould 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 intenfeiy bitter, 
more fo than the ftrongeft decoction of common bark. Its aftrin- 
gency 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 tincture of the red bark is alfo proportionally ftronger 
than that of the pale. The quantity of matter extracted by rectified 
fpiri.t from the powder of the former, was to that from the latter as 
3 to 2 in one experiment, and as 229 to 130 in another; and yet 
on infufing 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. 
Refpecting the medicinal properties we have feveral refpe stable 
authorities, fhewing, that as the red bark porTefTes the fame virtues 
* * 
with the common, in a much higher degree, J fo it has been found 
of more efficacy in the cure of intermittents : and hence it is thought 
to be that which, according to Arrot, the Spaniards called Cafcarilla 
colorada, 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 practi- 
tioners, that the bark iirft employed here was of a much deeper 
colour than the common bark. a The red bark was firft imagined 
by Dr. Saunders b to be that of 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 fubjed he fays, 
" that he has lately feen fome exceedingly good red bark imported: 
by a Spanifh merchant, a confiderable part of which was as fmall as 
* Lewis, Lev % Irving' $ and Skeete's Experiments. 
* Baker. Med. Tranj. Vol. Hi. p. 161. h Obfervations on the fuperior efficacy of 
the red Peruvian Bark in the cure of fever u 
* 
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