Chemistry. RXV 
nected with light or heat that it seems requisite to notice are some 
which originated from the curious discovery made some years 
ago by Sir H. Davy, that a fine platinum wire if plunged red-hot 
into mixtures of some of the inflammable gases and oxygen, or 
into mixtures of the vapour of alcohol or ether with common air, 
continues red-hot till the combustible bodies are consumed. In 
this case the combustion goes on without flame, sufficient heat 
being evolved to keep the wire red-hot. This curious discovery 
was soon after adapted to a common spirit lamp ; and such lamps 
being at present quite common in this country, it seems unne- 
cessary to give any description of them here. Davy has lately 
ascertained that the vapour of camphor may be employed instead 
of that of ether or alcohol for this experiment. 
Mr. Dalton and Dr. Henry have examined whether in combus- 
tions carried on in this way the carbon of the alcohol be converted 
into carbonic acid, or into some gaseous compound, containing 
less oxygen. The result of their experiments was, that no other 
compound of carbon, except carbonic acid, was formed.— 
(Annals of Philosophy, xii. 245.) 
II. SUPPORTERS. 
Very little addition has been made during the course of 1818 
to the knowledge which we already possessed respecting these 
bodies. The only new facts that I am aware of are, one respect- 
ing iodine, by Lampadius, and a numerous set of experiments on 
cyanogen, by Vauquelin. This substance, though not strictly 
oma a supporter of combustion, yet seems to be entitled to a 
place very near them, as it unites with hydrogen, and forms with 
it an acid, as is the case with all the supporters, except oxygen. 
I am induced on that account to place the new facts discovered 
respecting it by Vauquelin under the title which stands at the 
head of this paragraph. 
1, Jodine —Lampadius has ascertained that iodine dissolves 
with great facility in sulphuret of carbon, giving it a dark reddish- 
eve colour. One grain gives a deep tinge to 1000 gr. of the 
iquid. 
2. Cyanogen.—Water, as is well known, dissolves about four 
and a half times its bulk of cyanogen gas. Water thus impreg- 
nated is transparent and colourless, has a strong and peculiar 
smell, and possesses acid properties. Vauquelin has ascertained 
that when this liquid is kept for some time, the cyanogen and a 
portion of the water mutually decompose each other. The water 
becomes brown coloured and deposits some brown flocks, and 
itis found to contain three new acids, each of which is saturated 
with ammonia. These acids are hydrocyanic acid, carbonic 
acid, and a new acid, which Vauquelin proposes to call cyanic 
acid, because he thinks that it may be a compound of cyanogen 
and oxygen. 
Water holding caustic potash in solution produces the same 
