PREPARATION OF MERCURIAL OINTMENT. 
Ill 
1000 grains of Bark collected April 1st, 1851, yielded .478 grs. Pruss. acid 
1000 " " " May 20th « .856 " « 
1000 « " « June 18th " 1.007 " " 
1000 " ll u August 28th " 1.134 " «« 
1000 u « " October 16th " 1.436 " " 
The bark used in the preceding experiments was taken from 
a nourishing tree in Philadelphia county. 
1000 grains of bark collected May 23d, from the trunk of a 
tree in Jersey, yielded .876 grains of prussic acid. 
1000 grains collected June 13th, from the trunk of the same 
tree, yielded 1.159 grains. 
In order to ascertain how the bark which has been kept on 
hand for a length of time compares with that freshly collected, I 
made an experiment about the middle of October upon some bark 
which had been collected during the previous spring, and found 
1000 grains to yield .567 grains of prussic acid. 
It being the opinion of several eminent members of the medi- 
cal profession, that this bark contained also phloridzin, a prin- 
ciple known to exist in the bark of the apple and of some other 
fruit trees, to the possession of which they supposed its tonic pro- 
perty might be owing, I made a number of experiments in the 
manner directed for the preparation of phloridzin, both upon 
old specimens of bark, upon fresh bark of the branches and 
trunk of the tree, and upon fresh bark taken from the root under 
ground, at several successive times, but in all instances failed 
completely to detect any indications whatever of the principle 
sought. 
ON THE PREPARATION OF MERCURIAL OINTMENT. 
Mount Holly, Jan. 22, 1852. 
To the Editor of the American Journal of Pharmacy : 
Dear Sir : — Some years since ,my attention was directed to 
some improved, or at least more economical way ol making mer- 
curial ointment, than that directed in the Pharm. of the U. S., and 
the Dispensatory of Wood and Bache, from the fact of its being 
very tedious and laborious ; connected with which the un- 
