NEW PREPARATION OP CINCHONA BARE. 49 
ART. XIII.— NEW PREPARATION OF CINCHONA BARK. 
M. Donovan, of Dublin, has collected a considerable 
amount of evidence from numerous medical authors, tend- 
ing to prove that the alkaloids of the barks, quinine and 
cinchona, &c./are not the only constituentswhich give those 
barks their medicinal properties, but that their anti-periodic 
efficacy depends, in part, upon other ingredients, and much 
upon the combination in which the alkaloids are found in 
the natural state of the bark. The sulphate of quinine is, 
at present, the form most commonly employed, but many 
authorities are adduced by Mr. Donovan, to show that it 
cannot in all cases be depended on. 
Under the impression that these preliminary points are 
proved. Mr. Donovan proceeds to relate his experiments, 
made with the view to obtain an agreeable preparation, 
containing all the virtues of the bark in a small bulk. 
" Hitherto/' he says, u there has been no way of exhibit- 
ing bark in its full powers, except in the state of powder, 
which, to most personSj is so disgusting a dose that it is 
rarely prescribed." The following is the preparation which 
he conceives accomplishes the purpose : 
Let eight ounces of yellow bark, in coarse powder, be 
digested with a pint of proof-spirit for a week, in a close 
vessel, with frequent agitation. The tincture is to be fully 
extracted by the screw press ; the residuum is to be digested 
with another pint of proof-spirit for a week, and the tinc- 
ture again expressed. The residuum is now to be boiled for 
half an hour with a pint of water, and the decoction strong- 
ly pressed out. The boiling of the residuum a second and 
a third time with a new pint of water is to be performed in 
the same manner ; and then the three decoctions, mixed, 
are to be evaporated by heat to eight ounces. It will be 
much the better if this be done in a vacuum. The tinctures 
vol. xi — no. i. 5 
