56 
EMPLASTRUM IIYDIIARGYRI. 
but the first essential for satisfactory movement is, that we shall agree amongst 
ourselves as to what precautions it is best to recommend to chemists, that may 
satisfy the desire of the public without undue inconvenience in the practice of 
dispensing. We can do nothing with the educational clauses, which he proposed 
should be added if these provisions were at any time embodied in a Bill, until 
we have settled the first point. 
Feeling the urgent necessity of some action in the matter, a committee was 
appointed some time ago by the Executive Committee of the Pharmaceutical 
Conference to inquire into it; surely the Council of the Pharmaceutical Society 
do not mean to stand idly by whilst such questions are mooted. 
Since writing the above I have received for perusal, through the courtesy 
of the Secretary of the Society, the report of the committee presented at the 
meeting of the Council last August. It is a great pity that this report was not 
printed in the Journal. The proposals contained in it seem to me almost un¬ 
exceptionable so far as they go, but it could never have been intended as a final 
report; it leaves off in the middle of the “ first act,” and is, in fact, only the 
beginning of the beginning. Still, I am informed that this committee does 
not now exist. 
TYSON’S PROCESS FOR BLUE PILL. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir,—Dr. Attfield having pointed out to me that my communication to your 
periodical of the 18th ult., with respect to Tyson’s process for Blue Pill, is liable 
to misconstruction, I shall be obliged by your affording me space for explanation. 
Any careful and informed reader would perceive that in alluding to the possi¬ 
bility of the poisonous chlor-amiduret of mercury being formed, I referred solely 
to the action of ammonia on the small quantity of calomel left undecomposed by 
the Liq. Potassse ; but all readers are not careful and informed, and therefore it 
may be necessary to state that the precipitate recommended by Tyson for making 
Blue Pill would consist principally of dinoxide of mercury, mixed with a little 
of the di-clilor-amiduret. The therapeutical effects, consequently, would not be 
by any means so violent as if the latter compound constituted the whole preci¬ 
pitate, as was the case in the instance which I cited in my former letter. But 
we like to use pure chemicals in medical practice ; we are not satisfied if our 
calomel contain even very small quantities of corrosive sublimate, and the re¬ 
spected Tyson would not, if he was aware of it, wish his black oxide to be con¬ 
taminated with chlor-amiduret. 
I find I was mistaken in supposing that Dr. Attfield approved unconditionally 
of Tyson’s process. He was, it appears, aware of its defects, and will, no doubt, 
perfectionate a much better and safer one. 
I am, Sir, yours respectfully, 
John Aldridge, M.D. 
Pharmaceutical Referee to the Pharmacopoeia Committee 
of the Medical Council. 
[We do not think there is any good evidence to show that Blue Pill owes its 
efficacy to the presence of oxide of mercury ; and there is one important objection 
to the use of black oxide of mercury, which is, that it becomes transformed very 
rapidly into the poisonous red oxide.—E d. Piiarm. Journ.] 
EMPLASTRUM HYDRARGYRI, Piiarm. Brit. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir,—Having had occasion to try the process directed in the new British 
