470 LECTURES ON THE BRITISH PHARMACOPOEIA. 
Now, some persons may perhaps be disposed to say that all this is of little 
importance, for what are the distilled waters but mere solutions of essential 
oils in water, and what can it signify how the solution is made, whether by 
diffusing the oils through water by means of spirit, or some absorbent powder, 
or by distillation, or in any other way ? There may perhaps be a slight 
difference in the results, but as the products are chiefly used as vehicles for 
more active medicines, the influence of such differences must be inappre¬ 
ciable. 
I have heard such remarks as these made with reference to this subject, 
but I feel assured that you entertain a very different opinion. The distilled 
w r aters are certainly among the mildest of our Galenical medicines, but this 
does not render it any the less necessary to attend to those details by which 
the greatest perfection may be attained in the products. If we put side by 
side some of these waters made by different processes, we shall find marked 
differences,—if, for instance we take cinnamon-water made from the oil, 
even by distillation, and much more if made by mere agitation with water, 
and compare it with the water obtained by distillation from cinnamon-bark, 
the difference is not merely fanciful or trifling, it is not unimportant with refe¬ 
rence to the properties of the product in a medicinal point of view. The 
water made by the first method is deficient in all the best qualities of good 
cinnamon-water. Much the same thing may be said of pimento-water, made 
in the one case by solution or distillation from the oil, and in the other case 
by distillation from the berries. The latter would be found to be better, and 
to keep much better than the former. 
It may be stated as a rule, that these waters, when made from seeds, or 
barks, or flowers, are best made by distilling these vegetable substances 
with water alone, and making no further addition to them. They are thus 
ordered to be made in the British Pharmacopoeia, and I believe no im¬ 
provement could be made upon the processes there given. When the flavour¬ 
ing constituents of the waters are derived from the herbaceous parts of plants, 
the results are different. We may sometimes get satisfactory results by dis¬ 
tilling herbs, such as peppermint, with water, but we cannot thus depend 
upon uniformity of results. The waters so prepared are more variable, and 
not generally so agreeable, as those made by distilling the oils with water. 
There are two of the waters in the British Pharmacopoeia in which the 
oils are directed to be used, namely, peppermint and spearmint, and they 
are the two which experience seems to indicate as those best prepared in that 
way. 
I cannot quit the distilled waters without making a few remarks on the 
subject of distillation as a pharmaceutical process. This is a very ancient 
and a very efficient process for the separation of the more subtle and often 
more active constituents existing in natural products, or resulting from ope¬ 
rations to which they may be submitted. The early chemists were curious, 
and laborious, and patient in the performance of this and other processes. A 
great variety of forms of apparatus were employed by them, and arrange¬ 
ments were adopted which, to the modern pharmaceutist, would appear strange 
and fantastical. Not only were there different forms of distillatory apparatus 
used, but heat of different kinds was applied, and to the products of these 
various modes of manipulation peculiar virtues were ascribed. Thus, in addi¬ 
tion to the distillation effected by the heat of a fire, the process was some¬ 
times conducted by the heat of the sun’s rays, and sometimes by the mild 
heat of fermenting animal or vegetable matter, the apparatus being in fact 
stuck in a hotbed. Now, shall we say that this was part of the absurd phi¬ 
losophy of those days, and to be disregarded, together with the vain pursuit 
of tiie philosopher’s stone and elixir vitce ; or may we not at least admit that 
