22 
ON DRUG-GRINDING. 
APPARATUS FOR DRUG-GRINDING. 
a a. The drug-mill. e e. The guiding-frame for stampers. 
b b. The stampers. c. The sifting apparatus. 
The sifting apparatus consists of a square wooden frame 
(c), in which there are five or six octagon-shaped holes for 
the reception of the sieves. This frame is suspended from 
the ceiling by four ropes or chains, and its peculiar motion 
is effected by a rotating crank working in a socket in the 
bottom of the frame. A very irregular and jerking motion 
is thus imparted to the frame, and from thence to the sieves, 
by the joint action of the revolving crank, and of the ropes by 
which the frame is suspended. The sieves employed in 
the process are the common drum sieves, 
The first operation connected with the grinding of drugs 
consists of drying them. If they are in large masses, they 
are cut or broken into small pieces to facilitate the drying 
process, and also to prepare them for being put under the 
