ON THE PROTO-IODIDE OF IRON, &C. 
119 
green, by which we may recognise an iodide with an excess 
of iodine. 
This preparation should be made extemporaneously ; it 
does not answer to keep it; left only for an hour in contact 
with the air, it begins to alter; one part of the iron absorbs 
oxygen, and is precipitated as a sesquioxide ; the iodine, 
which is hence set free, is dissolved, and communicates to the 
liquid a reddish brown color, the more intense in proportion 
as the decomposition proceeds. The decomposition of the 
proto-iodide of iron takes place in a full and well stopped bot- 
tle, which may be explained by the decomposition of water 
effected by the action of protosalt of iron. 
Practitioners should not prescribe the normal solution by 
drops, since it cannot be preserved; neither can it be kept in 
a diluted state, as a potion or tisane, for, even in these mix- 
tures, its alteration is very rapid. 
2. Syrup of Proto-iodide of Iron. 
J& Normal solution of proto-iodide of iron, 4 grammes. 
Colorless and very thick syrup of gum, 200 " 
Syrup of orange flowers, 50 u 
Mix exactly by shaking for some moments. 
Remark. — It is indispensable that the syrups of gum and 
orange flower should be colorless, that the physician may 
have an assurance that the medicine is not altered. It is also 
useful to give to these syrups more than ordinary consistence, 
that the normal solution may not render them too fluid; a cir- 
cumstance which would facilitate the alteration of the proto- 
salt by contact with the air. Maintaining this precaution, the 
syrups of the proto-iodide of iron may be preserved for a 
month, and even longer; a necessary circumstance for a pa- 
tient who is distant from an apothecary. 
Each spoonful of the syrup represents very nearly four 
drops of the normal solution. 
We may mix, without inconvenience, this syrup, but only 
at the moment when it is to be taken, with a cupful or half a 
