THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[May 3, 1873. 
802 
a layer of it must be constantly maintained above the 
powder, so as to prevent the access of air to its inter¬ 
stices, until all has been added, or until the requisite 
quantity of percolate has been obtained. If the fineness 
of the powder and its arrangement in the percolator have 
been properly attended to, the percolate will pass out, by 
drops, with greater or less rapidity, according to the size 
of the percolator; but if, by reason of accidental imper¬ 
fection in the powder, or in the packing, the liquid pass 
more rapidly than this, the neck of the percolator should 
be obstructed by means of a cork until the requisite slow¬ 
ness has been attained. When the dregs of a tincture are 
to be subjected to percolation, after maceration with all 
the menstruum, the liquid portion should be drained off, 
the solid portion packed in a percolator as before described, 
and the liquid gradually poured on until all has passed the 
surface, when, immediately, a sufficient quantity of the 
original menstruum should be poured on to displace the 
absorbed liquid, until the prescribed quantity of the tinc¬ 
ture has l een obtained. 
“ Fineness of Powders .—As different degrees of fineness 
are necessary in powders, according to their nature and 
mode of treatment, the special degree required is de¬ 
signated in the several formulas. 
“ For this purpose the terms very fine, fine, moderately 
fine, moderately coarse, and coarse are used; the powder 
passed through a sieve of eighty or more meshes to the 
linear inch being designated as very fine ; through one of 
sixty meshes, fine; through one of fifty meshes, moderately 
fine ; through one of forty meshes, moderately coarse; and 
through one of twenty meshes, coarse. ” 
Substances that are likely to swell much after 
packing, although they may have been moistened 
previously with the menstruum, are generally ordered 
to be packed in a conical percolator, e. g. four troy- 
ounces of bitter orange peel in moderately fine powder, 
moistened with two fluid ounces of diluted alcohol, 
are directed to be packed in a conical percolator, 
and diluted alcohol q. s. added, that the required pro¬ 
duct, 32 fluid ounces, may be obtained. A cylindrical 
percolator is ordered to be used for the preparation 
of tincture of aconite, the powdered root of which is 
not liable to swell under the influence of alcohol. 
Mr. Ince once cynically remarked that French 
pharmacy, judged by the Codex, might be summed up 
in one word— sugctr ; American pharmacy might be 
summed up in— percolation. The process undoubtedly 
has many advantages over simple maceration, but the 
committee rides its hobby too far when it directs 
bitter orangey,eel to be used in the state of “ moderately 
fine powder ” to enable it to be percolated in making 
the tincture. What aroma or flavour,—for which it 
is generally used,—such a tincture will possess our 
readers may judge for themselves. The process of per¬ 
colation which has been described above can be con¬ 
ducted with cleanliness and little chance of contami¬ 
nation, yet with doubtful economy. But the principal 
objection, as I hope to show more fully hereafter, is 
the difficulty of getting the drugs into a sufficiently 
fine state of powder without, in many cases, their 
undergoing great deterioration, and also much likeli¬ 
hood of contamination in the process of powdering. 
The Committee of Revision having come to the con¬ 
clusion that the percolation of a drug in any state, 
except in the finest powder possible for it to be per¬ 
colated, does not exhaust it, has therefore ordered 
the drugs to be used in that condition only. But 
as the powdering of many substances will necessarily 
have to be done on a large scale, such processes will 
be the means of throwing the preparation of these 
medicines into the hands of manufacturers, who will 
be distinct from retailers and dispensers of medicines. 
The same may be said of a great number of the Ga¬ 
lenical preparations, the fluid extracts more particu¬ 
larly. This, although in many cases the division of 
labour may tend to perfection, will not, I think, be in 
the interest of the pharmacist and the public. The 
pharmacist likes a home-made preparation on which 
he will stake his professional and business integrity; 
the public also will suffer, for, owing to the competi¬ 
tion in trade, and there being no tests easily devisable 
for the strength and purity of such preparations, the 
public, through the retail pharmacist, will often be 
supplied with what is comparatively worthless. 
The principal solvents employed in making the 
preparations are ;— 
1. Water. —“ Natural water in the purest attainable 
state.” Excepting in rare cases where it is absolutely 
necessary to have distilled water, common water is 
directed to be used for all Galenical preparations, even 
for making the decoctions, infusions, tinctures, extract, 
and fluid extinct of the cinchonas, where one *would 
have thought the use of distilled water was clearly 
indicated. 
2. Distilled Water. —This is directed to be used in 
making most of the chemical preparations. 
3. Alcohol. — “ Spirit of the specific gravity 0*835,” 
—that is, absolute alcohol with 15 per cent, of water; 
it is 57*5, O. P., and is therefore a little stronger than 
our rectified spirit. 
4. Diluted Alcohol. — 11 Alcohol mixed with an 
equal measure of distilled water,” sp. gr. 0941. This 
is absolute alcohol with 61 per cent, of water. It is 
weaker than our proof spirit which contains 51 per 
cent, of water. 
5. Stronger Alcohol. —“ Spirit of the specific gravity 
0*817,”—absolute alcohol with 8 per cent, of water. 
6. Glycerin. Sp. gr. 1*25.—This is the same as 
our official glycerine. It is largely used as a solvent, 
mixed with alcohol and water in various proportions, 
in making the fluid extracts and a few other prepara¬ 
tions ; and as much depends upon its purity, the fol¬ 
lowing qualitative tests are given :—“ When mixed 
with twice its bulk of cold sulphuric acid it does not 
produce a brown colour. When diluted with water 
it affords no precipitate with hydrosulphate of ammo¬ 
nium, ferrocyanide of potassium, nitrate of barium, 
oxalate of ammonium, or nitrate of silver.” 
7. Acetic Acid. Sp. gr. 1*047.—This contains 36 
per cent, of the monohydrated acid, and is slightly 
stronger than our acidum aceticum, which contains 
33 per cent. only. In making the aceti, diluted 
acetic acid, 1 to 7 of distilled water is employed; but 
distilled vinegar , it is stated, may be substituted for 
it in making these preparations. 
8. Sherry Wine. —This is used as a solvent in all 
the vini, but no definition is given of it or of Port 
Wine , which is also official. 
These, or mixtures of them, are the solvents gene¬ 
rally used : their strength should be borne in mind 
in making any comparative investigations as to the 
merits of their preparations in comparison with our 
own. The new favourite, which, like several of the 
articles in the materia medica list, is a “peculiar”* 
* It is difficult to conceive how the term “peculiar” is 
at all descriptive of the substances to which it is applied. 
Camphor is said to be “a peculiar concrete substance;” 
amylic aloohol “ a peculiar alcohol;” guaiac resin “a, pecu¬ 
liar resin;” yeast “a peculiar insoluble product of fermen¬ 
tation;” musk “a peculiar concrete secretion;” creasote 
“ a peculiar substance;” and castor, spermaceti, and yellow 
wax are all “peculiar.” 
