38 Dr. Hancock on 
disgust, and often lies a heavy indigestible load on the sto- 
mach. Such considerations may one day appear of more im- 
portance than at present, when the prevailing infatuations 
respecting quinine and the new alkaloids shall have subsided, 
and given place to the exercise of sober reason and the exa- 
mination of new doctrines by careful experiment. 
I shall here notice the results of a few chemical experi- 
ments made on this bark, although I must confess I consider 
their action to be of very little consequence in elucidating the 
medicinal powers of any vegetable remedy. Gelatin forms 
with the infusion a precipitate of a reddish brown colour. 
Emetic tartar, nitrates of silver and mercury, acetates of lead 
and of alumina, all throw down precipitates of a light yellow 
colour ; sulphate of copper affords a gray, and sulphate of iron 
a greenish blue precipitate. ‘The carbonates of potash and 
soda render the infusion red brown, but form no precipitate. 
Lime water first renders the infusion green, then deep red, 
and throws down a copious precipitate of the same colour. 
These experiments were made for the sake of comparison, 
consecutively with others, on infusions of cinchona of more 
marked sensible qualities, but which I could not refer with 
any certainty to their species. The results were in some 
cases similar, in others widely different in respect to the ac- 
tion of reagents; i.e. on the infusion of the Juribali and the 
cinchonas. 
The recent decoction or infusion is of a red colour, but re- 
mains turbid forsome days. After infusing it for two or three 
weeks, it gradually assumes a deep red tinge, more transparent, 
having deposited a flocculent sediment. In this state it gives 
a durable red colour to stuffs, and precipitates the infusion of 
galls, which the recent infusion does not. 
It hence seems to be probable that, by a combination, or 
through some slight acidity, the infusion possesses the power 
of dissolving an alkaline principle, perhaps cinchonine, which 
is not taken up by pure water, or at least is not indicated in 
the recent infusion. It might be interesting to ascertain if 
the sulphuric or muriatic acids would evolve an alkaloid 
similar to those which are found in certain species of the genus 
cinchona. 
The bark contains a resinoid extractive, which is soluble in 
boiling water, but not in cold; the decoction, therefore, be- 
comes turbid on cooling, and gradually deposits a red powder. 
This deposit is soluble in alcohol, and appears to be a simple 
resin, and not the active principle of the bark; it is insipid 
when washed in cold water. From this, and some other expe- 
