and of a New Gaseous Bi-carburet of Hydrogen. 323 



take place in the dark, and are, of course, quite indepen- 

 dent of the action of the sun's rays or of light. The new 

 gas may be kept over mercury for an indefinite time without 

 undergoing any apparent change ; but it is slowly absorbed 

 by water. Recently boiled distilled water, when agitated 

 in contact with the new gas, absorbs about its own volume 

 of it ; but, on heating the aqueous solution, the gas is 

 evolved apparently unaltered. The gas is absorbed to a 

 certain extent by and blackens sulphuric acid. 



The new gas detonates powerfully with oxygen, especially 

 when the latter forms three-fourths or more of the mixture, 

 and the only products appear to be water and carbonic acid 

 gas. It requires for its complete combustion 2J volumes 

 of oxygen gas, two volumes of which are converted into 

 carbonic acid gas, and the remaining half volume into 

 water. From the author's analysis by different methods, 

 the new gas appears to be composed of one volume of 

 hydrogen and two volumes of the vapour of carbon con- 

 densed into one volume. Its density is therefore less than 

 that of olefiant gas by the weight of a volume of hydrogen 

 equal to that of its own bulk. It is, in fact, a bi-carburet 

 of hydrogen composed of two proportions of carbon and 

 one of hydrogen, and may be represented by the formula 

 C* + H, or 2C + H ; and its constitution seems to differ 

 from that of any other known gas. 



From the brilliancy with which the new gas burns in 

 contact with the atmosphere, the author thinks it is admir- 

 ably adapted for producing artificial light, if it can be pro- 

 cured at a cheap rate. 



Article IL 



On the Atomic Weight of Nichel and its Oxides. By 

 Thomas Thomson, M. D., F. R.S. L. & E., Regius Pro- 

 fessor of Chemistry in the University of Glasgow. 



In a paper entitled " Observations on the Atomic Weights 

 of Bodies," published in the third volume of the Recoi'ds 

 of General Science, I adopted (see page 255) 3*625 as the 

 atomic weight of nickel, because that number agreed better 

 with the specific heat of that metal, stated by Dulong and 

 Petit, at 0-1035, supposing the law that the atomic weight 



Y 2 



