ON THE GALENICAL PROCESSES AND PREPARATIONS. 
469 
I may occasionally digress into the regions of speculation ; and this may serve 
in some degree to enliven what would otherwise be a rather dull subject. 
Aquce .—The distilled waters used in medicine are a class of preparations to 
which little importance is attached by some persons, who view them as mere 
vehicles for more active medicines, and therefore undeserving of much atten¬ 
tion. The method of preparing them has been frequently changed, and for 
some years past the object aimed at appears to have been to simplify and 
render as easy and expeditious as possible the processes for their production, 
rather than to give to the products qualities of which they are susceptible, and 
which would add to their medicinal efficacy. 
The processes given in the London, Edinburgh,"and Dublin Pharmacopoeias, 
have all differed, and I think I may say they have all been to some extent 
wrong. The London College have, for most of the waters, authorized two 
modes of preparation: the one consisting in distilling the seeds, bark, or herb, 
from which the medicinal properties are to be derived, with water; and the 
other in mixing the essential oils, previously obtained from those sources, 
with powdered silica and distilled water, and then filtering the mixture. 
There are two exceptions to the liberty thus given to adopt either of two pro¬ 
cesses, and they are in the cases of Rose water and Elder-flower water. The 
Edinburgh College, while they give a sort of implied sanction for the use of 
essential oils, by stating in their introductory remarks that the distilled waters 
‘ may also be prepared for the most part by agitating the volatile oils of the 
plants with water and filtering the solution,” nevertheless direct in the pro¬ 
cesses given that the vegetable substances—seeds, barks, herbs, etc.—should 
be distilled with water and a small quantity of spirit, three fluid ounces of 
rectified spirit being used in the production of a gallon of the distilled water. 
Then, again, the Dublin College order the “ waters ” (for they do not call 
them “ distilled waters ”) to be made by mixing alcoholic solutions of the 
volatile oils with distilled water, and filtering the mixtures. 
Now, of these several processes, taking them all together, it may be said 
that while there are good ones among them, there is nothing in the Pharma¬ 
copoeias to show which are good and which bad; and in every case, except 
two, where good processes are given, they are accompanied by a permission, 
if we think proper, to adopt another, which is a bad process. 
I consider the processes of the Dublin College objectionable, because, as a 
rule, these waters cannot be made in the greatest state of perfection by dis¬ 
solving the volatile oils in water, and because the addition of spirit is calcu¬ 
lated to produce an injurious effect upon the product. The processes of the 
Edinburgh Pharmacopoeia are also objectionable, for although in most cases 
the waters are directed to be prepared from the right sources by the proper 
means, namely, by distillation, yet the result is in some degree marred by the 
addition of spirit, which, instead of promoting the preservation of the waters, 
as was no doubt intended, has been found to induce acetous fermentation, 
and thus cause the waters to become acid. It is in the London processes, of 
those I am now referring to, that the best processes for distilled waters are 
to be found; but even here the good are so mixed up with bad, that it is just 
a chance which happens to be adopted. 
In the British Pharmacopoeia much judgment has been manifested in the 
adjustment of the processes for the distilled waters. All that was bad in the 
previous Pharmacopoeias has been carefully weeded out, and all that was 
good has been judiciously retained. The waters are all made by distillation, 
and by distillation with water alone, without any spirit. Some of them are 
made by distilling essential oils with water, and others by distilling the vege¬ 
table substances containing the essential oils; and in all these cases I think 
the right processes have been indicated. 
