FLAMES OF COMPOUNDS OF CARBON AND HYDROGEN. 417 
artificial supply of air. Two methods occurred to me of effecting this object, so as 
to convert the carbon into carbonic acid, without its intermediate separation in a 
solid form. One was to burn the vapours of the substances under examination 
in the Bunsen lamp; but this I rejected as inconvenient, and perhaps even in 
some cases dangerous, from the risk of explosion, where it would have been 
necessary to boil highly volatile liquids in close vessels. The other was simply 
to pass a stream of air through the flame by means of a table blowpipe. By 
means of the latter expedient I succeeded so completely in preventing the sepa- 
ration of solid carbon, as to obtain spectra with bright lines and dark spaces, 
in the case of every compound of carbon and hydrogen which I have as yet sub- 
mitted to examination. 
Comparison of the Spectra of the Flames of various Substances containing Carbon and 
Hydrogen. 
The hydrocarbon compounds which I have examined, and which are enu- 
merated in the following table, may be divided into two classes; one consisting 
of substances containing only carbon and hydrogen, of which the general formula 
is C,H,, and the other of substances containing carbon, hydrogen, and oxygen, 
represented by the formula C, H, 0,. 
C, H, 
Light carburetted hydrogen, Cc H, 
Olefiant gas, : 4 Cc, H, 
Paraffin, 3 A : . . C,,, Hy, 
Oil of turpentine, : ¢ : : : : C,, H, 
C, H, O; 
Methylic alcohol, E . fj : : Coe AO: 
Alcohol, : 5 : : 6 é C, H, 0, 
Ether, ° 4 1 3 ; t 5 Cc, H, O 
Methylic ether, C,H, 0 
Glycerine, . : d : : é : CaO: 
Spermaceti, - ; : ; : 4 C,, H,, 0, 
Camphor, ; BR eth) 706) 
Wax, : : , 3 é : 3 
Tallow, . : 3 3 F - ; Of indefinite 
Coal gas, . ° A é - : : composition. 
Coal naphtha, 
Of these substances, the light carburetted hydrogen was made by heating 
_ acetate of soda, hydrate of potassa, and quicklime ; and the methylic ether from 
- wood spirit and sulphuric acid. The gases were generally burned from a platinum 
jet, immediately after passing through a tube filled with pieces of quicklime. 
_ The glycerine, a substance which burns with difficulty, was heated in a platinum 
capsule; and the paraffin, camphor, and spermaceti, which were colourless, crys- 
talline, and apparently pure specimens, were also similarly treated, in order to cor- 
roborate the conclusion stated at p. 415, that the lines observed in the spectra were 
