628 
ON SO-CALLED CARBOLATE OF IODINE. 
A Committee was also formed to consider the question of prices, and, after some 
deliberation, submitted a revised list to the members, which was unanimously approved, 
and at once adopted. The greatest harmony and good feeling prevailed ; and a reso¬ 
lution was passed to the effect, that they should meet every three months for the dis¬ 
cussion of matters of mutual interest. 
BIRMINGHAM CHEMISTS’ ASSISTANTS’ ASSOCIATION. 
At a General Meeting of the above Association on Tuesday evening, March 22nd last, 
a present was received from Messrs. Evans, Sons and Co., of Liverpool, of a materia 
medica cabinet, containing various specimens of a large variety of drugs, suitable for 
candidates for the Major examination. A cordial vote of thanks was passed to the 
donors, and the evening was spent in examining the specimens. It was determined to 
have materia medica papers and classes on alternate meeting nights. 
ORIGINAL AND EXTRACTED ARTICLES. 
ON SO-CALLED CARBOLATE OF IODINE. 
BY WALTER G. SMITH, M.B. DUBL., 
FELLOW AND CENSOR COLL. OP PHYS., ASSIST. PHYS. ADEL. HOSP. 
A preparation bearing this title has lately been brought into notice, under the 
synonym of “ Colourless Tincture of Iodine.” The chief advantage claimed for 
it is that it leaves no stain or mark on the linen or skin, while it is left to be in¬ 
ferred that its beneficial effects are similar to, if not identical with, the tinctura 
iodi of the British Pharmacopoeia. 
In the ‘American Journal of Pharmacy* for 1868 a formula was given for 
“ Colourless Tincture of Iodine,” indicating the following proportions :—Com¬ 
pound Tincture of Iodine, m 45 ; Carbolic Acid, crystallized, fused, pi 6 ; Gly¬ 
cerine, 5 viij ; Water, * v. It was stated that the colour of the iodine gradually 
disappears, and much more quickly if heated ; that the change was due to the 
carbolic acid, and not to the glycerine ; and that the iodine was probably trans¬ 
formed into iodoform. No doubt if iodine, carbolic acid, and glycerine are 
mixed together, and especially if heat be applied, some of the iodine is deco¬ 
lorized ; but this is, in all likelihood, due to a partial conversion of the iodine 
into hydriodic acid. 
It was paradoxical, and indeed beyond belief, that free iodine could exist in 
a colourless solution ; and as I was aware that such a preparation had been 
adopted in practice by some medical men, I thought it worth while to test 
qualitatively the nature of this vaunted new (?) compound. The specimen I 
examined, derived from a well-known source, had a slightly acid reaction, an 
unmistakable odour of carbolic acid, and possessed a sweetish taste, followed by 
a pungent tarry flavour. 
When added to starch paste, no blue coloration was developed unless nitric 
acid were first added, consequently there was no free iodine. Heated with 
slaked lime, ammonia was abundantly evolved. It was now evident how the 
iodine was rendered colourless through the formation of iodide of ammonium, 
and indeed I had previously been given to understand that the vendor of this 
preparation, finding that the iodine solution was not entirely decolorized by 
the carbolic acid and glycerine, took the liberty of adding some ammonia to 
complete the process. Treated with tartaric acid and starch, no blue colour was 
formed, and hence the absence of iodate may be concluded. Some of the ori- 
