78 CONVERSION OF COMMON INTO RADIANT MATTER. 



Carburetted-hydrogen, or bi-hydroguret of carbon, is that 

 gaseous substance, which exhales in hot weather from stagnant 

 pools and ditches of water, in the neighbourhood of towns. 



Dr. Dalton first determined with accuracy its composition, 

 and Sir H. Davy published experiments on it in 1811. It is 

 colorless, has neither taste nor smell, specific gravity 0.555 : 

 when a jet of this gas issuing from a tube is kindled in the 

 open air it burns with a yellow flame, giving out a good deal of 

 light ; when mixed with oxygen gas, and that it receives an 

 electric spark, it detonates with considerable violence. It does 

 not burn unless the bulk of the oxygen rather exceeds its own 

 bulk, and it actually ceases to burn when the oxygen is in 

 greater proportion than 2J times its volume. If mixed with 

 atmospheric air it burns, provided it amounts to l-12th of the 

 air, and it ceases to burn if it exceeds l-6th of the air. 

 In all proportions between these two extremes, it burns with 

 violence : for complete combustion it requires twice its volume 

 of oxygen gas, and produces exactly its own volume of carbonic 

 acid gas ; the only remaining other product is water. This is 

 according to Dr. Thompson, chap. iii. page 243, who concludes 

 that carburetted-hydrogen is composed by weight of, 



Carbon 0.416 0.750 3 



Hydrogen 0.0694x2 0.125X 1 



or one atom of carbon, and two atoms of hydrogen. 



Sir H. Davy observes, the fire produced in a number of 

 chemical processes, particularly in combustion, on the New- 

 tonian view, may be ascribed to particles sent into free space, 

 in consequence of the repulsion excited by other particles at 

 the moment of their uniting into chemical union. Any solid 

 bodies may be made to emit light, when exposed to a blast of 

 air very hot, though not luminous, the light is always of the 

 same kind ; and this circumstance is favourable to the idea of 

 the possibility of the conversion of common matter into radiant 

 matter. 



In radiant matter the particles act almost independently of 



