US REMARKS ON OLEO-RESINOUS ETHEREAL EXTRACTS. 
lateral opening of the Woulf's bottle, a glass or tin tube 
(d) is carried to the upper part of 
the cylinder a, where it is inserted, 
as shown in fig. 13. The cold 
water in the vessel c is renewed 
through the pipe e, which conducts 
it to the bottom, while the warm 
water runs off from the top through 
the pipe f. Hot or cold water is renewed to the space 
between the two cylinders (R,) by the tube-funnel h, and 
the water from this space overflows into g, and is carried 
off together with that from /. The tube h is inserted through 
a perforated cork at i, so that, by turning the tube down- 
wards, the water from the space between the cylinders can 
be thus allowed to run off. 
The method of operating with this apparatus will now 
• be easily understood. The substance, in coarse powder, is 
placed upon the perforated strainer in the space marked R» 
(fig. 12,) over a piece of flannel, cut to the size of the 
strainer. Ether is now poured over the substance to be 
operated upon, and allowed to percolate through it and run 
into the Woulf's bottle. The tube d is fixed in its place, 
and cold water is introduced into the space between the 
cylinders a and b, and into the vessel c. The bottle is now 
immersed in hot water, so as to cause the ether which has 
run into it to boil ; and the vapour passing through the tube 
d into the upper part of the vessel R, is condensed there by 
the action of the surrounding cold water, and again passes 
in the liquid state through the substance to be exhausted. 
This circulation of the ether may be continued, without 
loss, until the solid substance is completely exhausted, which 
will be indicated by the ether dropping into the bottle 
colourless. 
The extraction is in this way effected very rapidly. The 
following results were obtained from the treatment of eight 
ounces of worm-seed with ether. The worm-seed, in coarse 
Fig. 13. 
