February i t 1373.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
601 
PERCOLATION. 
BY ERNEST C. SAUNDERS, A.P.S. 
My attention lias recently been drawn to several 
papers appearing in the Journal on percolation, and 
different processes of maceration. The subject ma}^ 
seem almost overdone, but I think that a process of 
such importance is worth all the attention that can 
be paid to it, especially as I think that it is hardly 
used as much among druggists, in preparing their 
tinctures, infusions, etc., as the great advantages it 
offers demands. 
In Mr. Schweitzer’s article, which appeared in 
the number of December 21st, there are several 
statements which seem to me hardly calculated to 
increase the efficiency of the process in inexpe¬ 
rienced hands, and I should like to mention a few 
joints which, in my own experience, appear to me 
cnost important. I must premise that I have rarely 
operated larger quantities than fifty pounds at a 
time, butdfeljtoe had to do with almost every drug 
in general u^*. 'and those who operate with larger 
quantities are comparatively lew. 
With regard to the form of percolator, I think it 
is too much to make the sweeping assertion that the 
cylindrical form is the best. For resinous sub¬ 
stances and for anything percolated with strong 
alcohol it undoubtedly is, but for such articles as 
orange-peel, gentian root, and cinchona bark the 
conical form is preferable. It is said that the coni¬ 
cal percolator does not exhaust the species at the 
junction with the sides, in consequence of the loose 
attachment to them, and of the slight pressure of 
the liquid at the top. I think that any one who has 
had much experience in percolating with glass ap¬ 
paratus must have noticed the gradual saturation 
ot the menstruum equally as much in passing down 
the sides of a conical percolator as in a cylindrical 
one; . while, after carefully watching and several 
experiments, I have come to the conclusion that 
pressure has nothing to do with the solvent power 
of the liquid, and that in some instances it acts in¬ 
juriously by causing the operation to go on more 
rapidly than is advisable. In percolating with 
either form of percolator, I never allow of more 
than one to two inches of menstruum on the sur¬ 
face of the drug, arranging that it shall be supplied 
so as to be of a uniform depth throughout the opera¬ 
tion. 
Drugs ought in all cases to be of a uniform de¬ 
gree ol fineness, according to their quality, and 
should be thoroughly moistened before being packed 
in the percolator. This is one of the most impor¬ 
tant points in the whole operation, as on it depends 
the possibility of successful packing in the case of 
all roots and dried herbs that will absorb much 
water. The amount of moisture should be only 
sufficient to form a slightly coherent powder, ca¬ 
pable of being pressed into a mass, but not, under 
any circumstances, of forming a paste. The direc¬ 
tions of the U.S. Pharmacopoeia are distinct and of 
great practical value in this respect. Such drugs as 
gentian, calumba, etc., should be left in a covered 
vessel from six to twelve hours after being moistened, 
to allow them to thoroughly absorb the liquid and 
expand to their full amount. 
In packing, it is always best to use the hand, and 
the occasions are very few where this cannot be 
done. I am surprised to see Mr. Schweitzer advo¬ 
cate the use of whole chaff and straw mixed with 
Third Series, No. 13 (>. 
the drug to increase the bulk. Such articles are 
among those most likely to cause a failure in the 
attempt to exhaust any drug, forming channels down 
which the menstruum will run, instead of being 
gradually drawn through the whole body of the 
mass, and equably penetrating every part. Also, 
when the drug is properly moistened and packed, it 
will never rise to the top of the liquid, and such 
clumsy expedients as weighting down the top with 
glass stoppers are entirely unnecessary. After pro¬ 
perly packing (an operation that nothing but actual 
experience can teach), all that is necessary is to 
cover the surface with filter-paper, not to keep the 
drug from rising, but to prevent the menstruum, as 
it is added, from stirring up the surface. If any of 
the drug should rise to the top, the operator may be 
certain that it is owing to its having been insuffi¬ 
ciently or improperly moistened. 
In conclusion, I must enter my protest against 
such preparations as Mr. Schweitzer recommends. 
There are many objections, but I will only mention 
the three principal ones. I will leave altogether 
out of the question the use of water as a menstruum, 
both on account of its inability to preserve the deli¬ 
cate active principles from decomposition, and of the 
impossibility of exhausting such drugs as orange- 
peel, cinchona bark, etc., with it. The objections°to 
such concentrated solutions, made with ordinary 
menstruum, are these First. The difficulty of pre¬ 
serving such strong solutions without change, owing 
to the gradual deposition of a sediment, carrying 
with it frequently a large share of the active prin¬ 
ciples. _ This is not a hypothetical objection, but 
one which actually arises frequently, as in this 
country many fluid extracts are in use made practi¬ 
cally in the manner suggested by Mr. Schweitzer, 
in which this change has often been noticed. 
Second. The impossibility, in many cases, of ex¬ 
hausting the species with so small a quantity of 
menstruum. It is needless for me to give any in¬ 
stances, as any one can see this at once on looking 
at the B.P. forms, and calculating to what bulk they 
would have to be reduced. Third. The increased 
facilities for adulteration and purposed diminution 
of strength; for were such extracts in general use, 
their manufacture would speedily fall into the hands 
of large makers, and competition would produce the 
inevitable results of lower prices and inferior quali¬ 
ties. Such preparations are largely in use in this 
country, and the above are the chief objections to 
be urged against their use. 
I think the difficulties of percolation have been 
very much overrated. In large quantities the diffi¬ 
culties are great, and only to be surmounted by 
much care and some skill; but in working witli 
small quantities the difficulties are very slight, 
while the results are so superior to those produced 
by the old process of maceration in general use, 
that I am sure any pharmacist having once tried it 
will never return to the old way. 
Detroit, Michigan. 
MILD ACONITES. 
BY M. C. COOKE, M.A. 
Supplementary to the observations already made 
on the Acrid Aconites of the East, some remarks 
may not be out of place on the milder forms, of 
which the “Atis’ is the type. Before doing this. 
