NOTE ON LINIMENTUM POTASSII IODIDI CUM SAPONE. 
35 
I procured some of this compound from Messrs. Dinneford and Co., M. Chan- 
teaud’s agents in London, and made the following simple experiments:— 
When a few grains are treated with cold water, the sugar, of course, is readily 
soluble, and it is manifest at once that the peroxide of iron is simply adherent 
to the surface of the crystals of sugar, for the peroxide almost immediately is 
detached from the sugar, and diffused mechanically through the solution, leaving 
the residue of the crystals of sugar perfectly colourless. The solution was fil¬ 
tered, and the filtrate acidified and tested with ferrocyanide of potassium, sul- 
phocyanide of potassium, and sulphide of ammonium. No precipitation or co¬ 
loration ensued, except the slightest possible tinge of blue with the ferrocyanide 
of potassium. The filtrate, on standing for some time, deposited an additional 
trace of peroxide, which was filtered off, and the resulting filtrate was perfectly 
colourless and transparent, and gave negative evidence with the tests for a ferric 
salt. 
So far, then, from its being “ perfectly soluble,” or “ only a trace of the iron 
remaining insoluble”* (see Pharm. Journ. May, 1869, p. 647), not a particle of 
the oxide of iron is really in solution. The peroxide would certainly be soluble 
in the gastric fluid, but it is erroneous to state that it is at all soluble in water. 
To determine the amount of peroxide present, which was evidently very small, 
the following experiments were made:— 
3*601 grammes ignited in a platinum crucible left 0017 gramme of Fe 2 0 3 
=(>47 per cent. The smallness of the result surprised me, and as I thought that} 
there might have been some mistake, I ignited, on another occasion, 3*6212 
grammes in a silver crucible, and obtained a residue of Fe 2 0 3 =0*0176 gramme, 
viz. 0*48 per cent. 
This percentage of peroxide of iron is almost homoeopathic, and to give a dose 
of this “soluble peroxide of iron” equivalent to 5 grs. of the ferri peroxidum 
hydratum, the minimuru dose in the British Pharmacopoeia, we should have to 
order nearly oz. (1041 grs.). 
A Dublin house has also quite lately put forward this preparation, or “rusty 
sugar-candy,” as it was aptly designated by a friend, under the specious title of 
Saccharated Crystallized Oxide of Iron (omitting, however, M. Chanteaud’s 
name), and “ its perfect solubility , and, as a consequence, its ready absorption 
into the circulation without any disturbance of the functions of digestion ” are 
enumerated as some of its points of advantage over other preparations of iron. 
Dublin , June 14, 1869. 
NOTE ON LINIMENTUM POTASSII IODIDI CUM SAPONE. 
The difficulty experienced in always producing a good result in making this 
preparation seems to depend on some slight difference which exists in Marseilles 
soap, even in different samples obtained from the same maker. 
To obviate this, it has been suggested to replace one-third of the hard soap 
with the same quantity of the potash soap of the Pharmacopoeia. This has been 
tried with perfect success, the liniment forming a jelly which does not separate, 
as is so often the case when made with Marseilles soap only, a slight difference 
in which is quite sufficient to prevent the formation of a good liniment. 
* We observe that Professor Chevallier, of the School of Pharmacy of Paris, Member of the 
Academy of Medicine, testifies to the solubility of this preparation in the following terms: — 
“ Chanteaud’s saccharated oxide of iron is soluble in distilled water, *nd its solution passes 
through a washed filter coloured and without residue.—E d. P. J. 
D 2 
