oj carbon and hydrogen y &c. 451 
bi-carburet of hydrogen, of which it would of course be a 
saturated solution at 0°. Its boiling point was very constantly 
186°. In its general characters of solubility, combustibility, 
action of potassium, &c. it agreed with the substance already 
described. Its specific gravity was 0.86 at 60°. When 
raised in vapour 1.11 grain of it gave*i.57s cubic inches of 
vapour at 212°, equal to 1.212 cubic inches at 60°. Hence 
100 cubic inches would weigh about 91.6 grains, and its 
specific gravity would be 43.25 nearly. In another experi- 
ment, 1.72 grains gave 2.4 cubic inches at 212°, equal to 
1.849 cubic inches at 60°; from which the weight of 100 
cubic inches would be deduced as 93 grains ; and its specific 
gravity to hydrogen as 44 to 1. Hence probably the reason 
why, experimentally, the specific gravity of bi-carburet of 
hydrogen in vapour was found higher, than by theory it 
would appear to be when pure. 
Sulphuric acid acted much more powerfully upon this sub- 
stance than upon the bi-carburet ; great heat was evolved, 
much discolouration occasioned, and a separation took place 
into a thick black acid, and a yellow lighter liquid, resisting 
any further action at common temperatures. 
0.64 grains of this substance were passed over heated 
oxide of copper ; 4.51 cubic inches of carbonic acid gas were 
obtained, and 0.6 grains of water. The carbonic acid and 
water are equivalent to 
Carbon - 0.573176, or 8.764 
Hydrogen - 0.066666 1. 
but as the substance must have contained much bi-carburet 
of liydrogen, it is evident that, if in a pure state, the carbon 
would fall far short of the above quantity, and the compound 
MDCCCXXV. 3 N 
