ON THE IODIDE OF AMIDINE. 
337 
us to regard this combination of iodine and amidine as solu- 
ble in water, contrary to the opinion of some chemists, who, 
since our experiments, have endeavored to prove, that this 
blue compound was only in suspension, in the liquid, in the 
state of extreme division. The observations which we had 
made at that time, and those of a more recent date, confirm 
our first observations. 
1. A solution of iodide of amidine prepared during the 
month of July, (1833,) by pouring a solution of iodine into 
the soluble part of fecula, obtained by treating with cold 
water bruised and triturated grain, was placed in a closet free 
from all luminous rays. This solution examined month by 
month, up to this time, during the four years that have passed, 
has not formed the least deposit. It had constantly the ap- 
pearance of a homogenous solution, equally colored in all its 
parts, of a fine indigo blue, and moreover constantly acted like 
a solution of iodide of amidine, recently prepared. The long 
lapse of time through which we have preserved, exempt from 
the action of light, this blue liquor, without its having sensibly 
lost any of its intensity, proves that this matter offers all the 
characters of a real combination, for the amidine itself, dis- 
solved in water, undergoes, in some weeks, a complete decompo- 
sition, or at least has lost the property of being colored blue by 
a solution of iodine. 
This fact, of which we are witness, presents in itself much 
interest on account of the stability of the compound of iodine 
with an organic principle under the circumstances related 
above, since its aqueous solution at the end of four years, pre- 
served with the care indicated, offered nearly the same physi- 
cal and chemical characters. 
2. The action of cold upon a solution of iodide of amidine 
has afforded us some new facts to corroborate the opinion 
which we have formed upon the true nature of this combi- 
nation. 
The solution of the iodide of amidine which was the object 
of the preceding observations, was exposed to the low tempe- 
rature of the last week of January; it congealed between 4° 
