of time to feparate more mild earth with the lime-water,
and more extracted matter. Lime-water as precipitating
the extra£ted matter appears an equally improper and
difagreeable menftruum'. Water has been found to fuf-
pend the refin by means of much lefs gum than has been
fuppofed. Rectified fpirit of wine extracts a bitternefs,
but no aftringency, from a refiduum of twenty affu-
fions of cold water; and water extradls aftringency,
but no bitternefs, from the refiduum of as many affu-
fions of rectified fpirit. The refidua of both are in-
fipid*.”
From many ingenious experiments made on the Peruvian
Bark by Dr. Irving, publifhed in a Diflertation which
gained the prize-medal given by the Harveian Society of
Edinburgh in 1783, the power o f different menftrua upon
Peruvian Bark is afcertained with greater accuracy than
had before been done : and it appears, that, with refpedt
to comparative power, the following fluids adt in the order
in which they are placed : Dulcified fpirit o f vitriol:
Cauftic lye : French brandy: Rhenifh wine : Soft water:
Vinegar and water: Dulcified fpirit of nitre : Mild volatile
alkali: Rectified fpirit of wine: Mild vegetable alkali
: Lime-water. The antifeptic powers of vinegar
and Bark united are double their fiim taken feparately.
The aftringent power of the Bark is increafed by acid of
vitriol; the bitter tafte is deftroyed by it.
* Ed. New Difpenf. p. 251.
. 2 . Though
Though the Bark on its firft introdudlion, and even
fome time afterwards, w s reprobated by Tome eminent
phyficians as a dangerous remedy ; yet thefe prejudices
are entirely done away, and its charadter is now universally
eftablifhed : fo that the difputes which at prefent
fubfift are confined to its mode of operation, or the manner
in which it is moft efficacioufly adminiftered. To detail
thefe, however, or even to give a circumflantial relation
of the various fiâtes o f difeafe in which the Bark
might be advantageoufly employed, would far exceed
our limits : we are therefore confined to flate briefly
thofe difeafes to which this medicine is more efpecially
adapted.
The Bark firft acquired its reputation for the cure of intermittent
fevers, and in thefe, when properly exhibited,
it rarely fails of fuccefs. For this purpofe, fome practitioners
prefer giving it juft before the fit, fome during
the fit, and others immediately after. Dr. Cullen, who
is of the firft opinion, fays, “ I am fatisfied that giving
a large dofe of the Bark immediately before the time of
acceflion, is the moft proper practice: but as that dofe
muft not be under two drams of pale Bark, fo there are
fome ftomachs which will not bear even that quantity,
or a larger that might be neceflary. It is commonly’
therefore, convenient to give finall doles, but to give them
every hour for fome hours near to the times o f acceflion*.”
p. 97.
Some