ON A NEW COMPOUND, ETC. 
229 
ever, is greatly diminished when it is close to the freezing 
point, and appears altogether prevented when a certain amount 
of iodide of potassium is present. 
When heated to 82°, the crystals melt into a dark liquid, 
from which, upon cooling, the original substance is reproduced. 
When heated beyond its melting point, iodine, and a vapor 
smelling strongly of oil of cinnamon sublime, and iodide of 
potassium is left behind, mixed usually with a little carbon, 
resulting from the decomposition of a portion of the oil. 
Starch would appear to decompose this substance, for with 
even its alcoholic or ethereal solution it forms the well-known 
blue compound. When agitated with water and zinc, or iron 
filings, an iodide of these metals is produced, and the oil is set 
free. With mercury the result is the same, and in each in- 
stance for water, alcohol or ether may be substituted. Potash, 
also, at once developes the oil, forming, as is the case of free 
iodine, iodide of potassium and iodate of potash. 
From these facts it seems legitimate to infer that it is the 
oil, and not any modification of it corresponding to the ben- 
zoyle of chemists, which is associated with the iodine and 
iodide of potassium, and that they are all held together by an 
extremely feeble affinity, inasmuch as not only is the iodide 
of potassium separated by water, as has been stated, but 
the iodine is affected by a solution of potash, just as if it were 
free. To test the truth of this opinion, a little of the com- 
pound was decomposed in a small glass retort by the exact 
equivalent of a very dilute caustic alkali, and, a receiver being 
applied, about half an ounce of a liquid, having the appearance 
and obvious properties of cinnamon water, was drawn off by 
distillation. From it, however, I could not, though every 
precaution was employed, procure a particle of the original 
crystalline compound. The properties, indeed, of the distilled 
liquid were not, upon an accurate examination, identical with 
those of cinnamon water. Its odor, for example, was slightly 
different, and it reddened litmus, a circumstance from which 
it may be inferred to contain cinnamic acid. It is therefore 
not unlikely that the oil may have absorbed oxygen, or have 
