298 Miscellaneous Intelligence. 
acid. Now, in their action upon the atmosphere in which they are 
consumed, the above three diluents present striking differences in these 
two respects. 
quantity of heat capable of heating 5 lbs. 14 oz. of water from 82° to 
212°, or causing a rise of temperature. from 60° to 80°-8 in a room 
containing 2,500 cubic feet of air. 
One cubic foot of carbonic oxyd at the same temperature and press- 
ure, consumes during combustion 4 a cubic foot of oxygen, generates 
one cubic foot of carbonic acid, and affords heat capable of raising the 
temperature of 1 |b. 14 oz. of water from 60° to 66°-6. 
One cubic foot of hydrogen, at the same temperature and pressure, 
consumes $a cubic foot of oxygen, generates no carbonic acid, and 
This comparison shows the great advantage which hydrogen posses- 
ses over the other diluents, especially over light carburetted hydrogen, 
which is evidently a very objectionable constituent, and shows that a 
normal gas for illuminating purposes should consist of illuminating ay: 
a mode of destruction which occurs so largely in the usual process of 
gas-making. This mode of treatment produces a gain in the amount 
of illuminating power derived from a given weight of coal, equal to 
from 50 tg upwards of 100 per cent., whilst the increase in quantily of 
gas is frequently 300 per cent. 
The gas thus manufactured differs principally from coal-gas made by 
| 
Carbonic acid. Heat. 
Tallow, - - = . 10-1 cubic feet 1 
2 > a re 2 a ‘6 yy 
Spermaceti, —- - - o3 : 
Sperm oil (Carcel’s Lamp), 4 ** 63 
g . 47 
adon gases, B, C, D, E; 
