1816.] during the Year 1815. 29 
combustible burns in the liberated gases with great brilliancy: 
When heated, it explodes with more violence than euchlorine ; and 
two measures of it seem to be converted into three, two of which 
are oxygen and one chlorine. This approaches the supposition that 
the compound is formed of 
Chlorine .... 1 atom | Oxygen .... 4 atoms 
But it is obvious that if the weight of an atom of chlorine be 
4°4, and that of an atom of oxygen 1, the two gases never can 
combine in one volume chlorine and two oxygen. Accordingly 
Davy found less than one volume of chlorine to two of oxygen. If 
we suppose 0°9 of a volume of chlorine to two volumes of oxygen, 
which was what Davy actually found, the substance will then be a 
compound of one atom chlorine and four atoms oxygen. 
Thus we have three compounds of chlorine and oxygen, namely, 
Chlorine, Oxygen. 
Euchlorine, composed of...... 1 atom + 1 atom 
New gas... eseveesecscnes | + 4 
Chloric acid... ...6ceeceevees 1 + 5 
It will be necessary to apply systematic names to these substances. 
I would recommend to Sir H. Davy to employ the Greek numerals 
in his nomenclature, because they apply to any quantity of com- 
ounds of the same constituents, without occasioning any confusion. 
hus his ewchlorine might be called protochlorous oxide; his new 
gas, deutochlorous oxide ; and Gay-Lussac’s chloric acid, perchloric 
acid. These names would be distinct, and much more easily re- 
membered than arbitrary terms given without any regard to system. 
We may affect to disregard system in our names, but the affectation 
is improper. Without attending to it, the science of chemistry 
becomes a mere mass of confusion. When our chemical theories 
are shown to be erroneous, let the names be altered. This does no 
harm, if it is not in reality attended with good. 
3. Iodine.—A great number of papers on iodine have been pub- 
lished during the course of the year 1815; but after the very com- 
plete treatise on that subject by Gay-Lussac, inserted in the fifth 
and sixth volumes of the Annals of Philosophy, these papers cannot 
be expected to exhibit much novelty. The following are the only 
new facts that I have observed in them. 
The iodide of gold is a white powder. Uranium is precipitated 
by a hydriodate of a dirty dark colour. Link, Fischer, and Steffens, 
(Schweigger’s Journal, vol. xi. p. 134.) 
_ The iodide of antimony has a dark red colour, and is soluble in 
water. The iodide of bismuth is orange. Its solution is not preci- 
pitated by potash. The iodide of arsenic is dark purple-red, and 
possesses acid properties. The iodide of tellurium is dark purple- 
red, and forms a colourless solution with potash. Ruhland. (Ibid. 
p. 139. 
. Dr. Wollaston has determined the figure of the crystal of iodine 
“to be a rhomboidal octobedron, whose axes are to each other as the 
