Page:Philosophical Transactions - Volume 104.djvu/574

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Sir H. Davy's further Experiments

It is evident from this experiment, that sulphur, iodine, and hydrogene, are capable of forming a triple compound.

2. I sublimed some iodine in dry olefiant gas; a little of a reddish brown fluid was formed, but the greatest part of the iodine crystallised on the sides of the vessel in which the experiment was made. By repeating the process several times, more of the fluid was formed. It was volatile at a moderate heat, and gave a yellow tint to water, but did not render it acid, there was a very slight absorption of the gas.

3. Iodine sublimed in nitrous gas effected no change in it.

4. When iodine was exposed to carbonic oxide it underwent no change, it was repeatedly sublimed in it in common day light without undergoing the slightest alteration.

When the violet gas was formed by heating iodine in carbonic oxide, and the vessel exposed for some time to the direct solar rays, a small quantity of a limpid fluid which had an acrid taste formed in the vessel. An accident prevented me from ascertaining if any gas had been absorbed, but it seems probable from this result that, like chlorine, iodine may be combined with carbonic oxide by the agency of light.


5. On the mode of detecting Iodine in combinations, and on certain properties of its compound with Sodium.

1. I have examined many of the marine productions of the Mediterranean, with the view of determining whether they contained iodine. The ashes of the fuci and ulvæ of this sea afford it in much smaller quantities than the sel de varec, and in a very few cases only have I been able to obtain evidences of its existence in them.