64 NEW PREPARATION OF IODINE, ETC. 
ART. XXI.— ON A NEW PREPARATION OF IODINE.— SYRUP 
OF IODIDE AND CHLORIDE OF IRON. 
By Samuel Battley. 
As iodine is at present so extensively employed, and 
maintains so high a character as a remedial agent, it ap- 
pears rather singular that some of its most efficient combi- 
nations are still so little used, x^mongst these the iodide of 
iron is one which has not yet attained that rank in profes- 
sional estimation that its merits claim. This seems in part 
owing to the process by which the London Pharmacopoeia 
directs it to be prepared, its great tendency to decomposi- 
tion, and the difficulty of its preservation. The iron pos- 
sesses a greater affinity for the oxygen of the atmosphere 
than for iodine, in consequence of which the latter is set 
free, and when the preparation is exhibited in such a state, 
the stomach is frequently incapable of bearing what might 
otherwise prove a valuable tonic. This tendency to oxida- 
tion in the iron, and liberation of free iodine, is indeed pre- 
vented by using the syrup, the sugar in which has the pro- 
perty of preventing protoxides, protiodides, and protochlo- 
rides, from absorbing oxygen, and passing into peroxide, in 
which state iron exerts but little action ou the system. 
Practical men, however, have remarked, that the iodide 
of iron, even when given in the best form, has sometimes 
failed to produce that speedy and decisive chalybeate in- 
fluence on the system that other salts do, though in other 
respects an agreeable and elegant form. This observation 
is readily explained on reference to4he constitution of the 
salt, in which the amount of iron is less than one-fourth of 
that of the iodine, the combining proportion of the former 
being 28, while that of the latter is 126. As iodine is in- 
capable of entering into combination with a greater propor- 
tion of iron, in order to increase the quantity we may sub- 
