166 
BRITISH PHARMACEUTICAL CONFERENCE. 
cury is simply in a very fine state of division, and my own experiments are only 
confirmatory of this fact: in no case has the trace of oxide present been at all 
adequate to produce the effects of blue pill. Nevertheless, mercury in its ordi¬ 
nary condition being inert, it is reasonable to suppose that some further change 
takes place in it before it affects the system ; what this change may be, it is no 
easy matter to determine, possibly it is oxidation in the stomach, so large a 
surface being exposed to the action of that organ. 
The specimens examined were repeatedly washed with distilled water, to re¬ 
move the soluble part, and then digested with hydrocyanic acid, by which any 
oxide present would be converted into cyanide and metallic mercury ; but mere 
traces only could be detected. The mercury was then separated by solution, in 
dilute nitro-hydrochloric acid, from which it was precipitated as sulphide ; other 
specimens were treated with dilute hydrochloric acid, which should have con¬ 
verted any suboxide or oxide present into subchloride or chloride ; the result was 
analogous to that obtained by the former process. 
The variation in colour, consistence, etc., in the commercial “blue pill,” led 
me to suppose that the mercury was in a much more finely divided state in some 
cases than in others, and this supposition was strengthened by the variable 
amount of boiling requisite to separate it. A microscopic examination at once 
proved this ; in some instances the mercury was so intimately mixed with the 
other ingredients of the pill mass, that no globules were distinguishable even 
with a high power, whilst in others they were easily detected by the aid of a 
pocket lens only. 
Assuming that every sample of “ blue pill,” in the market, contains the proper 
proportion of mercury, it is still an unsatisfactory preparation, lacking that uni¬ 
formity of condition so desirable in a medicine, and especially in one so com¬ 
monly prescribed as this. The process by which it is made, is one so tedious 
and difficult that very few pharmaceutists attempt to prepare it for themselves. 
One of the largest makers informs me that, in order to amalgamate them, he 
grinds the ingredients together for thirty hours, under a pair of millstones, 
weighing 1^ tons each. 
The directions of the Pharmacopoeia are somewhat indefinite,—rub the ingre¬ 
dients together “till globules are no longer visible.” Now, supposing this ob¬ 
ject to have been accomplished, we have a “blue pill,” containing mercury, in 
a finely divided state, but let the mass be still further triturated, and the metal 
will be yet more finely divided,—it being rather difficult to place a limit to the 
divisibility of a fluid. Thus, multiplication of particles may be carried on ad 
infinitum , and probably the activity of the pill proportionately increased ; it is, 
therefore, very desirable that some process be devised by which the Pharmaceu¬ 
tical Chemist can make his own pil. hydrarg., and which shall yield a product 
of uniform composition. By such a process I have prepared some specimens 
(shown to the meeting). They are of a beautiful blue colour, and the minute 
state of division in which the mercury exists in them may be easily demonstrated 
by suspending a few grains in a glass of water. 
The mode of preparation I have adopted, is as follows:—136 grains of chloride 
of mercury (corrosive sublimate) are dissolved in 4 oz. of distilled water, and the 
solution raised to the boiling-point: an ounce of protochloride of tin is then put 
into a beaker with 2 drms. of hydrochloric acid, and 2 oz. of cold water, to 
which, when dissolved, the mercurial solution is added, and the mixture stirred 
for a few seconds. The precipitated mercury, in the form of a nearly bktck 
powder, is then allowed to subside, washed several times by decantation with 
dilute hydrochloric acid, to remove any traces of tin, and finally with distilled 
water. It would, of course, be impossible to dry and weigh this precipitate 
without causing the excessively minute particles of mercury to unite into one 
globqle ; but, as we know that 136 grains of chloride yield 100 grains of me- 
