16 
ORIGINAL COMMUNICATIONS. 
recipient, first inserting a sufficient quantity of straw in the 
neck of the funnel, I pour my materials, settling them by 
slight agitation, then disseminate absolute alcohol, by portions 
at a time, over the surface, until the whole is made to pass in 
this way. The filtration goes on rapidly, and, at the end of 
the operation, nothing is perceived in the funnel but the 
straw, sand, and impurities which were contained in the 
resin. The solution is perfectly limpid, and possesses the 
proper requisite of a varnish body . It was considered by 
• those in the habit of using it, equal in every respect to the 
other. 
I succeeded by the same means in forming with myrrh a 
fine tincture, in a very expeditious manner. The alcohol at 
first passes off replete with all the peculiar fragrance of the 
myrrh, and imbued with a deep reddish color, gradually 
fading towards the close of the operation, until nearly color- 
less. 
At its termination I passed water over what remained in 
the funnel, and obtained an opaque, yellowish solution, having 
the odor and taste of myrrh in a less sensible degree, which 
by evaporation yielded the extract of myrrh sometimes needed 
in medical dispensation. After this there remained but a 
small quantity of residuum, displayed in the form of a gelati- 
nous mass of mingled white and yellow, together with some 
extraneous matters reposing upon the straw. 
I also made some tincture of benzoin by displacement; the 
first that passed over was very dark in color; this was suc- 
ceeded by an amber colored producf, and the last that passed 
was colorless, leaving a residuum small in quantity and chiefly 
of fibrous matter. 
Furthermore, some aloes and guaiacum, severally submitted 
to this treatment, proved additional auxiliaries in evidence of 
its power. 
It is obvious to every one that this method possesses a de- 
cided advantage over the ordinary one for the preparation of 
the tinctures of the resins and gum resins, not only with re- 
gard to economy of time, but especially its nicety and perfec- 
