MINUTE DIVISION OF MERCURY. 
251 
with acetic acid ; and when dry, the mercury appeared as 
usual on the filter. The same experiment was tried, substi- 
tuting mel despumatum for syrup. The honey, in the first 
instance, divided the mercury more readily than the syrup, 
but the completion of the division was ultimately expedited 
by the addition of enough sugar to give it the right con- 
sistence. 
These experiments confirm the supposition that chemical 
action is not necessarily concerned in the division of mercury 
by trituration, but that the effect depends upon the mechani- 
cal texture of the substance employed. 
An additional proof of this fact is found in the extreme 
difficulty of effecting the extinction of mercury with a dry 
substance like chalk, as compared with the effect of other 
more appropriate substances. To obviate this difficulty in the 
hydrarg. cum magnesia of the Edinburgh Pharmacopoeia, the 
mercury is directed to be triturated with manna, moistened 
with a little water; after the union is complete, the magnesia 
is added, the manna separated by washing, and the precipitate 
dried. 
The following experiment with blue pill is as conclusive 
as those already mentioned : Blue pill was boiled in water, 
and the sediment having subsided was washed several times to 
separate the conserve. The result was placed on the filter, 
and allowed to dry spontaneously. As long as it retained a 
soft consistence very little appearance of mercury was obser- 
vable — it was like a black paste. But in the course of a few 
days, it became quite hard and brittle. When broken be- 
tween the fingers the greater portion of it fell down in the 
form of pure mercury. A simple fracture displayed a surface 
of extremely minute globules in a spongy substance. It was 
evident that the whole of the conserve had not been separa- 
ted, but the experiment was sufficiently accurate for the 
purpose. 
The late Mr. Earle recommended a pill composed of one 
drachm of mercury with five drachms of extract of hemlock, 
which, by trituration for a quarter of an hour, become com- 
VOL. VIII. — no. m. 32 
