SYRUPUS FERRI IODIDI. 
335 
I hope the results of these few experiments may prove useful to some of the 
readers of your valuable Journal. 
Blackburn. 
SYRUPUS EERRI IODIDI. 
BY T. H. HUSTWICK. 
After all that has been said and written on this well-worn subject, one might 
almost be tempted to think that nothing more remains to be said as to its pecu¬ 
liarities. I am, however, induced to offer the following remarks as the result 
of my experience iu making this syrup. The manner thereof I learned during 
my apprenticeship, and from the superior results obtained by it, have used the 
same ever since. Of course I do not presume to entertain the idea that I am by 
any means the only one, or even one of a select few, who are possessed of this 
process ; but that there are some who are unacquainted with it, is evidenced by 
the correspondence to which it has given rise in this Journal. 
The process is this, and is equally applicable to the formulse of the old and 
new pharmacopoeias. To produce the quantity there ordered, the iron wire 
well rubbed with sand-paper is cut into lengths of about f inch, aud put into 
a flask with, say, 4 oz. of water; these are boiled till the iodine colour has dis¬ 
appeared ; the solution is filtered into an evaporating-basin containing the sugar 
in coarse powder, heat is applied to this while the filtration is proceeding, and 
the filter is being washed, it is then brought to the boiling-point as rapidly as 
possible, and the gas flame extinguished ; when cool, sufficient water is added 
to make the required measure. The resulting preparation is clear, colourless, 
and will keep unchanged any reasonable time. It will be seen that this process 
differs from that of the old Pharmacopoeia, in adding the iodide solution to the 
sugar, instead of the sugar to the solution; from that of the new, in adding 
the solution to sugar instead of to syrup, and from both in the application of a 
higher degree of heat. It seems to me, that by adding the solution to the 
sugar, a slight degree of oxidation is prevented, whilst the boiling-heat ensures 
a more perfect combination. It is worthy of note, that Mr. Carteighe, in his 
paper read before the last Pharmaceutical Conference, touches upon this latter 
point, and he is the only one of your correspondents who notices it; he says, 
“ that if the syrup is heated rapidly to boiling, before adding the iodide 
solution, the preparation has less colour than if made at the lowest temperature 
at which sugar will dissolve.” He also speaks of the u original colour ” of som« 
of his specimens being bleached by exposure. And Mr. Holloway, in his letter 
of April, 1868, also notices the fact of the acquired colour being discharged by 
similar means ; in both of which cases it seems that length of time and exposure 
produce similar effects to what a higher degree of heat applied at the first does, 
excepting that with the greater heat a more permanent result takes place. My 
experience prompts me to say, that syrup of iodide of iron, properly prepared, 
should have no “ original colour” whatever, but only the very pale sea-green 
tinge peculiar to a freshly-prepared solution of the iodide. 
My stock of the syrup has been made considerably over six months, and kept 
in a common green glass bottle in one of the shop cupboards, whence it is used 
as occasion requires, and yet, without any of the precautions that have been 
so frequently suggested, it is as free from colour now as on the day it was 
made. 
I would remark, that as rapidity of manufacture is an element of success, it 
is better to use the finest iron wire in preference to tacks, as the wire presents 
a larger surface to the action of the iodine, and combination, therefore, more 
quickly takes place. The process is simple and easy, requiring no more than 
