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Selected Articles . 
two fluids became mingled. By this series of experiments 
M. Guilliermond concludes that the process of displacement 
may be advantageously employed in the preparation of ex- 
tracts whenever the vehicle employed is only intended as a 
solvent and has nothing to do with the medical qualities of 
the article. But if the displaced fluid is intended to form a 
tincture, any attempt to operate its displacement by water 
will give rise to error, and therefore an analogous fluid should 
be employed. 
Jour, de Phar. 
ART. LXIIL— ON SPONGE. — By A. Baudmmokt. 
Sponge is a marine production, classed by zoologists, in the 
animal kingdom. That in common use is formed of an im- 
mense number of extremely delicate fibres, which are crossed 
and interlaced in a variety of directions, and thus form fibres 
of different shapes, which are perforated by an infinity of 
small holes in every part. Whilst alive they are covered with 
a viscous and tenacious slime. They are attached to rocks 
and the most part of those found in commerce are obtained 
in the Mediterranean. Several varieties are to be met with 
in the market, the principal are : 
Fine Syrian Sponge. — This sponge is usually in the form of 
a conical shallow cup, with sometimes sharp and at others, 
rounded edges ; it appears to be covered with a multitude of 
harsh, short hairs. Its external surface is convex, and is 
pierced with very fine holes, but its internal surface has large 
openings in many parts of its superficies. When first taken 
from the sea it is almost white, but after having been washed 
and prepared it becomes of a yellow fawn colour ; it some- 
times occurs in very large pieces and may be bleached with 
great ease. It comes packed in hair bags of different weights. 
Fine Archipelago Sponge. — This is closely allied to the pre- 
