12 
Mr. Brande on the composition and analysis 
common purposes of illumination ; the coal gas being that 
supplied from the Company’s works in Westminster, and the 
oil gas furnished by the decomposition of common whale oil, 
in an apparatus erected for that purpose by Messrs. Taylors 
and Martineau, at Apothecaries’ Hall.* These gases have 
been submitted to analysis by different chemists of eminence ; 
and we are more especially indebted to Dr. Henry for a 
series of valuable researches respecting their production and 
composition. -f It is therefore with considerable diffidence that 
I venture to propose views relating to them in many respects 
different from those of my predecessors in this important 
branch of chemical inquiry. 
It is generally admitted, that there are two definite com- 
pounds of carbon and hydrogen ; the one, usually termed 
olefiant gas, consisting of one proportional of carbon and one 
of hydrogen ; and the other called light hydrocarburet , com- 
posed of one proportional of carbon and two of hydrogen : 
the former of these gases appears to have been discovered in 
1796) hy the associated Dutch chemists, Messrs. Bondt, 
Dieman, van Troostwick, and Lawerenbourg,^ and the 
other first examined by Mr. Dalton. § Assuming hydrogen 
as 1, the specific gravity of olefiant gas is 13,4 ; and it con- 
tains 1 proportional of carbon =5,7 + 1 proportional of 
hydrogen = 1. Light hydrocarburet has generally been 
* A description and plate of this apparatus is given in the Quarterly Journal 
of Sciences, &c. Vol VIII. p. 1 20. 
f Nicholson’s Journal, Vol. XI. p. 65. Philos. Trans. 1808. Manchester 
Memoirs, Vol. III. New Series. 
£ Journal de Physique, XIV. § New System of Chemical Philosophy. 
