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ORIGINAL COMMUNICATIONS. 
give this method their sanction, by adopting it in general, or 
recommending it in particular cases, in the work which will 
result from their labors. We do not wish to be understood 
as advocating a process because of its novelty, but only on 
the solid and substantial basis of its own intrinsic merits. We 
have extensively employed it in pharmaceutical operations, 
and, consequently, speak from experience. All we ask from 
those who may undertake a verification of our statements, 
is the same devotion, care, and precision, in the labor of in- 
vestigation, which attended our experiments, if they wish to 
obtain equally definite results. These observations are the more 
necessary, as the greatest success depends upon the dexterity 
and attention which may be given to the experiments, for it 
can hardly be expected that a clumsy operator will, in any 
instance, draw favorable results. 
EXTRACTS. 
The best prepared extracts should not be black, but more 
or less brown in color, except when viewed in mass, and 
when held up to the light, should be transparent. They should 
have the characteristic taste, as well as odor, when it posses- 
ses any, of the plant used to make the extract, and should not 
have a burnt taste. A great variety of the extracts in present 
use, particularly the narcotic, as imported from England, con- 
tain a large quantity of chlorophylle, and have a greenish, 
unctuous appearance ; their light green color has given rise 
to the supposition that a portion of the powdered leaves was in- 
corporated with them. With water, they make a very turbid 
solution, depositing a sediment upon standing, and leaving a 
great deal of insoluble matter upon the filter. 
In preparing an extract, very large quantities of water are 
employed in successive boilings, to exhaust the plant of its 
virtues, all of which must be evaporated, to the detriment of 
the quality of the products. By displacement, this is avoided, 
as the substances, by ceding their soluble principles to very 
small quantities of water, enable you to obtain highly concen- 
trated solutions. 
