26 Improvements in Physical Science [JAN- 
4. Olefiant Gas.—In the year 1811 I published in the first volume 
of the Memoirs of the Wernerian Society of Ediaburgh a paper on 
the gaseous combinations of carbon and hydrogen. In that paper 
(p. 516) I detailed some experiments which I made on the oily-look- 
ing substance formed by the action of chlovine on olefiant gas. From 
these experiments I drew as a conclusion that the substance in ques- 
tion was not an oil, but a compound of olefiant gas and chlorine. 
This conclusion has been recently contirmed by the experiments of 
Robiquet and Colin (Ann. de Chim. et Phys. i. 337), who prepared 
considerable quantities of the Jiquid in question, and examined its 
properties considerably in detail. They obtained it by passing a 
current of chlorine and olefiant gas (both pure) into a large glass 
globe. The liquid was freed from its excess of chlorine, if any 
happened to be present, by washing it with a little distilled water. 
Thus prepared, it possessed the following properties :— 
It is colourless as water. It has an agreeable odour, very similar 
to that of muriatic ether. its taste is sweet, sharp, and rather 
agreeable. Its specific gravity, at the temperature of 44°, is 1:2201, 
that of water being unity. ‘The density of its vapour, at the tem- 
perature of 48°7°, is such that it supports a column of mercury 
24-666 inches in length. Hence its boiling point is 152°. The 
specific gravity of its vapour, according to the experiment of Gay- 
Lussac, is 3°4434. It burns with a green flame, emitting a thick 
smoke, and depositing a good deal of charcoal. It is composed of 
one volume of chlorine and one volume of olefiant gas condensed 
into one volume. Now the specific gravity of 
CIGAR CME hein sn megainprany iden eels «0/050, 2ISOU 
INEM ADE BAB ae sine Mperaisrareincs ing s3 4°» «yee ee 
3°47 4 
Thus we see that the oil is equal to the specific gravities of these 
two gases united, as it ought to be. 
Muriatic ether, on the other hand, is composed of 1 volume of 
muriatic acid + 1 volume of olefiant gas condensed into one 
volume. Hence the reason of its greater volatility, and less specific 
gravity. The supposed oil of the Dutch chemists, then, is chloric 
ether; or, if a systematic name should be preferred, it may be 
called chloride of olefiant gas. 
5. Arsenical Hydrogen Gas.—It is sufficiently known to chemists 
that it was during a set of experiments on the preparation of this 
gas that Gehlen lost his life. Professor Schweigger has lately made 
us acquainted with the process which he followed. It consisted in 
heating a mixture of arsenic in the state of powder and a concentrated 
alkaline ley. (Schweigger’s Journal, xv. 501.) ) 
6. Phosphureted Hydrogen.—In a late number of the Annals 1 
published a set of experiments on thfs gas, hitherto but little exa- 
mined. It may be obtained by putting pieces of phosphuret of 
