32 
ON DRUG-GRINDING. 
The first column of figures in the table represents the 
whole quantity of the specified drug which has been ground 
at several different periods; the second column indicates the 
greatest amount of loss on any one specimen; the third co- 
lumn indicates the smallest amount of loss on anyone speci- 
men, and the last column gives the average upon the whole. 
It appears from this table that the average loss in powder- 
ing drugs is more than four per cent, in nearly all cases, and 
that in some it is considerably more. Now, it could not be 
reasonably supposed that the drug-grinder would in any 
case supply good rhubarb or jalap, gentian or ginger, for the 
water which had been imbibed in a damp warehouse or 
cellar. If he be required to make up a certain quantity of 
powder, evidently more than the crude drug produces, how 
is he to do it ? Is he to keep a stock from which to supply 
the deficiencies of all the drugs he grinds, and go to market 
and purchase more when his stock is exhausted, or is there 
magical power in his mill ? 
A drug-grinder's mill is a very different thing from the 
pestle and mortar of the druggist, although they are both 
employed for the same purpose. The druggist, when he 
has used the pestle and mortar, cleans them preparatory for 
the next operation, by washing them with water. The drug- 
grinder also requires to clean his mill. Rhubarb must not 
be ground after aloes, nor ginger after jalap, without 
previously well cleaning the ponderous stones and other 
parts of the apparatus. But how shall this be done ? A drug- 
mill cannot be cleaned by washing it with water — if for no 
other reason, it would be objectionable on account of its 
making the room and apparatus damp, which are required 
to be perfectly dry. Instead of water, sawdust is used for 
cleaning the drug mill. After grinding any drug, in order 
to remove the adhering particles from the mill, sawdust is 
ground until the mill is rendered sweet and clean. 
Sawdust, then, is indispensable at a drug-mill, as neces- 
sary as water is in a druggist's shop, and if the druggist 
