300 
PHARMACEUTICAL MEETING. 
the true Pharmacopoeia acid, they adopted the following label in Mae ink , which 
is sufficiently explicit. 
TO MAKE THE 
ACIDUM ACETICUM DILUTUM 
OF THE 
PHARMACOP. LONDIN. 1851, 
TAKE OF 
This Acid by weight. 15 parts. 
Distilled Water by weight 85 parts. 
The following are memoranda of the results of a very careful analysis I made 
of the three acids just named. The experiments were repeated twice or three 
times, and confirmed by my friend and colleague in the Pharmacopoeia work, 
Dr. Redwood. The specific gravities were taken in 1000-grain bottle, and the 
estimation of the acid was made with carbonate of baryta. 
Beaufoy’s Acetic Acid. 
* 
Contains of 
Anhydrous 
Acid per cent. 
To make the 
Acid. Acet. Dil. 
of the P.L. = 
4*6per cent., use 
of Acid to 
Water. 
To make the 
Acet. Acid. Dil. 
of the P.E. = 
3* per cent.,use 
of Acid to 
Water. 
To make the 
Acet. Acid. Dil. 
of the D.P. = 
3*oper cent.,use 
of Acid to 
Water. 
1 to 7 sp. gr. 1040*5 
24*25 
1 in 5*27 
1 in 8*08 
1 in 6*93 
1 to 9 „ 1047*5 
30*02 
1 in 6*52 
1 in 10*00 
1 in 8*57 
1 to 11 „ 1056*0 
141-00 
1 in 8*91 
1 in 13*66 
1 in 11*71 
The Acid. Acet. Dil. of the P. L. 1824, contained of anhydrous acid 4*6 per cent. 
The Acet. Destill, of the P. L. 183G, contained of anhydrous acid 4*6 per cent. 
The Acid. Acet. Dil. of the P. L. 1851, contains of anhydrous acid 4*6 per cent. 
The Acidum Aceticum of the same Pharmacopoeia contained of anhydrous 
acid 30-8 per cent. 
By which it appears that there has been no alteration in the strength of the 
preparation for nearly forty years. 
The present formula for Acid. Acet. Dilut. is acetic acid = 30*8 per cent., 
23 drs. fluid , distilled water to fill 20 fl. oz. = 160 fl. drs. = 1 in 6-956, or in 
round numbers 1 in 7, and not 15 to 85 = 3 to 17 = 1 to 5-66, unless the latter 
proportions be very carefully made by weight. ( Vide Phillips’s Translation of 
the Pharmacopoeia, London, 1851, page 50.) 
If the foregoing statement be correct, it will appear that to make the Acid. 
Acetic. Dil. of the present London Pharmacopoeia 4-6 per cent, of anhydrous 
acid, the following should be the strength of the acids marked respectively 1 to 7, 
1 to 9, and 1 to 11, namely :— 
1 to 7 should be 36*81 instead of 24*25. 
1 to 9 „ 46*04 „ 30*02. 
1 to 11 „ 51*21 „ 41*0. 
I suppose the new forthcoming National Pharmacopoeia will help us out of this 
great difficulty, otherwise the first step towards it would be for the manufacturer 
to send out the acid of the London Pharmacopoeia with this simple label:— 
* These numbers so nearly agree with the following, given to me by Beaufoy and Co., that 
practically there is no difference:— 
1 to 7 . . . 1040* . . . 24*25 
1 to 9 . . . 1048* . . . 30*08 
1 to 11 . . . 1056* . . . 41*00 
> 
