THE SPECIFIC GRAVITY OF T1NCT. FERR1 PERCHLORIDI. 
841 
9 > 
Belladonnas Extracti . 
Morphiae Muriatis . . . 
gr. xxx 
AEtheris Rectificat. . . 
f 5 viij 
Chloroformi. 
f 5 vii J 
Acid. Hydrocyanic, dil. . 
f 5 iv 
Olei Menthae Piperitae 
xxx 
Capsicine. 
Misturae Acaciae . . . 
5 xx 
Caramel. 
* 
5J* 
Theriacae. 
. . ad 
M. s. artem. Whether Dr. Browne’s chlorodyne contains more or less than is 
represented in the above formula 1 cannot say, neither do I attempt to assume 
decisively upon this point. Of course it is possible, although I deem it impro¬ 
bable, that it may contain some subtle ethereal compound undetected by either 
chemist or physiologist; and, although my formula contains belladonna,—thus 
differing from Mr. Smith’s,—I am quite sure that the fair, impartial, and accu¬ 
rate clinical observer must feel assured that chlorodyne, prepared according to 
Mr. Smith's formula, does contract the pupil , thus differing from Dr. Collis 
Browne’s; that chlorodyne, prepared according to my formula, does not contract 
the pupil, thus agreeing in its action with Dr. Collis Browne’s ; these observa¬ 
tions applying only to ordinary doses. 
Medical Club, May 1 6th, 1870. 
THE SPECIFIC GRAVITY OF TINCT. FERRI PERCHLORIDI. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir,—My letter to you on the 22nd of April has opened up the whole ques¬ 
tion, not only of “ What is the specific gravity ofi the tinot ferri perchloridiV ’ 
but also, What is the real gravity ofi the liq. ferri perclilor. fiortior ? for the an¬ 
swer of the first question is involved in the second. It is rather surprising that, 
notwithstanding the statements of Mr. Abraham, of Liverpool, in Pharm. Journ. 
Yol. IX. p. 272, and of Jardine, Yol. VI. p. 549, the error as to gravity in the 
B. P. is perpetuated, not being even in the list of errata printed after the pub¬ 
lication of the Pharmacopoeia. It is in consequence of this omission that I felt 
it incumbent upon me to settle the question for my own guidance, if not for the 
satisfaction of others, seeing that no two operators had arrived at precisely the 
same result; and practically it is a matter of very considerable importance, 
when we consider that, on a large scale, the instructions of the B. P. cannot be 
literally followed, and that the gravity is the test that will be adopted as the 
standard of strength. The following are the various statements that have been 
published :— 
British Pharmacopoeia . . . L338 
Mr. Squire.1-420 
Mr. Yewdall.1-339 
Mr. Jardine.1*433 
Mr. Abraham . . . 1-445-1 "449 
Here is sufficient confusion to distract the steadiest judgment. 
In order to gain for the result I have arrived at the confidence I trust it 
deserves, it will be necessary to give the details of the operation. 
Whatever may be the merits or demerits of the instructions generally given 
in the Pharmacopoeia, there is plenty of scope in this instance for the exercise 
of judgment and skill. The character of the vessel to be used is not named. 
VOL. XI. 3 I 
