, 
154 REPORT—1845. 
_ with 277-27 cubic centimetres of aqueous vapour. The eudiometric analysis 
gave the following result :— 
Volume. vaup i Pressure. 0° C.1m. 
° m 
Volume of gas used. .,.sep:sereeseeseereeees te : 2:3 0:4127 54:06 
Volume after admission of Oxygen ...+.....+6 03 0°6289 219°10 
Volume after COMbUStION.......c+eeeseeeeeneeees ‘ 0-2 05277 127:25 
Volume after absorption of carbonic acid ...| 182°8 | —3 0°4794 88°61 
Volume after admission of hydrogen ,,....... 3003 | —25 0:5952 180:39 
Volume after COmbuStION ......+eeeesseeseeeeeeee 10671 | —1:7 0:3987 42°57 
Volume after another admission of hydrogen| 295°0 | —1-7 0°5863 174-04 
Volume after combustion .........:..csseeeereeeee 106-2 | —1°5 0-4194 44:79 
In these data, and also in all those which follow, the tension caused by the 
aqueous vapour formed during the combustion is never neglected, and the 
correction necessary for it at the given pressure is already brought into the 
calculation. A simple consideration of these experiments gives us the fol- 
lowing values for the elements necessary to the calculation :— 
D 
ae 2°2993, 
A = 5406, 
B= 76:02, 
C = 38°64. 
These quantities lead us to the following composition : 
Light carburetted hydrogen... +-73°18 
Carbonic oxide ..........s.0.000. -- 14°08 
Hydrogen y..sesseccesccocsssseeee — 8°89 
OIPHBIG GAO wxccccdvenaccenxpscess | — eee 
In this case, therefore, the formula leads to an impossible result, which 
proves that other constituents must be in the mixture of gases. From these 
facts we may also derive another conclusion. If we deduct in the last four 
experiments the excess of oxygen left after the combustion from the volume 
of gas measured after the absorption of carbonic acid, the remainder will 
give the nitrogen originally contained in the mixture, or that liberated by 
the combustion. This calculation shows that the nitrogen = 0°01, from 
which we conclude that the gas from coal, distilled and collected as we have 
described, does not contain in appreciable quantity nitrogen, cyanogen, or 
any other nitrogenous substance. Hence it follows that the gaseous mix- 
ture must contain, in addition to the hydrocarbons already mentioned, others 
of unknown composition. It was now quite necessary to ascertain positively 
whether perchloride of antimony completely effected the separation of the 
latter as well as of olefiant gas. This question is easily decided by conduct- 
ing coal-gas freed from carbonic acid and sulphuretted hydrogen through a 
Liebig’s potash tube containing perchloride of antimony, behind which is 
placed another containing potash for the purpose of arresting the volatile 
perchloride, and a tube filled with chloride of calcium to prevent the escape 
of aqueous vapour. The gas treated in this way is collected over mercury, 
and exploded with the necessary quantity of oxygen, which is determined 
as well as that of the carbonic acid generated; and the proportion of the 
latter to the amount of aqueous vapour produced is obtained by leading an- 
other portion of the gas over red-hot oxide of copper. With this knowledge 
