16 
ORIGINAL COMMUNICATIONS. 
aware that this occurred after a full exposure to air and light 
for two weeks. 
3d. Three drachms of the solution, as before, was mixed 
with two drachms of simple syrup, and the mixture exposed 
for five days to air and light. On examination, the solution 
remained perfectly unaltered, not communicating the slightest 
tinge to starch water, or exhibiting any precipitate whatever. 
The vial was then corked, and left exposed to the light. 
Twenty-two days after the commencement of the experiment, 
the first evidence of free iodine was manifested, and to this 
time, nearly two months from that date, the solution remains 
so little altered that the presence of free iodine is hardly per- 
ceptible, and the deposit of oxide equally minute; there being 
none whatever on the sides of the bottle. 
4th. Three drachms of solution of protiodide of iron was 
mixed with one drachm of honey, and the mixture filtered, 
to render it perfectly transparent, and then exposed to air and 
light for three days without being the least affected. Twenty 
days after, the solution remained unchanged, and one month 
had elapsed before the slightest trace of free iodine could be 
detected. Two months after decomposition had progressed 
so tardily, that if no other protective agent existed, this would 
be better than iron. 
5th. Three drachms of the iodous solution were mixed with 
one drachm of uncrystallizable honey. The mixture was 
treated precisely as in the last experiment, and was found to 
answer more effectually than the unaltered honey. 
6th. Three drachms of the solution, as before, was mixed 
with two drachms of uncrystallizable sugar, (of molasses.) 
The mixture was then exposed several days to light and air 
without the slightest alteration. Nearly two months have 
elapsed since the beginning of the experiment, and not 
the slightest trace of free iodine, or of oxide, have been se- 
parated, notwithstanding it has been tested twenty times with 
solution of starch. 
7th. To exhibit the protecting power of these agents more 
pointedly, two vials, with wide mouths, were nearly filled 
