318 
MISCELLANY. 
Ointment of Mercury and Belladonna, By Dr. Mignot. 
R — Double mercurial ointment 30 
Extract of belladonna - 4 
Aqueous extract of opium - - - 1 
Liquid balsam of Peru - - - - q.s. 
Mix and F. S. A. an ointment of ordinary consistence, and perfectly 
homogeneous. 
This preparation is indicated in cases of hemorrhoidal tumors, whose 
pains it calms with much success. 
More or less numerous applications are made according to the cases. 
The dose in which it should be employed necessarily varies according 
to the size of the tumors, on the surface of which it should be ap- 
plied. — Ibid, from Jour, de Chim, Med. 
On a Method of Constructing a Simple Hydrometer. By Edward 
Thompson, Agent of the College of Chemistry, Otley. — .Chemists have 
frequently occasion to determine the specific gravity of a liquid when 
they have not access to an accurate balance and specific gravity bottle, 
and druggists may often find it convenient to be acquainted with a 
cheap substitute for an instrument which, as ordinarily purchased, is 
either expensive or extremely inaccurate. I think the simple contri- 
vance which I am about to describe, may be found useful under such 
circumstances. The scientific reader will perceive that it is a modifi- 
cation of an instrument proposed long ago by Fahrenheit: — 
Choose a light cylindrical four-ounce phial, and make a mark with a 
file or diamond completely round the lower part of the neck. Fit it 
with a bung which extends considerably over the neck of the phial, and 
which is scooped out on the upper surface in the form of a cup. Then 
introduce into the phial so much shot or pieces of metal as will float 
the instrument up to the mark in distilled water, at the temperature of 
60°, when a weight of about 500 grains is placed in the cork cup. N ow, 
ascertain the weight of the instrument, including the phial, shot, and 
cork, and it is complete. When the specific gravity of a liquid is to be 
ascertained, pour out the liquid into a vessel sufficiently capacious to 
float the hydrometer, and add weights to the cup until the surface of the 
liquid exactly coincides with the mark. The specific gravity may then 
be found by the following proportion : — 
As the weight of the hydrometer, added to the weight required to sink 
it to the mark in distilled water — 
Is to 1,000:— 
So is the weight of the instrument added to the weight required to 
sink it to the mark in any given liquid — 
