The following table exhibits the comparative amounts of water which can
be, under perfect conditions, evaporated from the substances named:
One pound burned. Water evaporated.
Hydrogen 64.28
Carbon (average of several experiments) 14.77
Carbonic Oxide 4.48
Sulphur 4.18
Alcohol 13.40
Oil gas 22.11
Turpentine 20.26
The last four substances are compounds, and the last three consist
almost wholly, or chiefly of carbon and hydrogen. The total heating
power of average coal is, it may be noted to advantage, about 12.83
pounds of water upon the same conditions as above described. Hydrogen,
it is seen, stands pre-eminently at the head of the list for heating
power, represented by the evaporation of 64-1/4 pounds of water, whilst
carbon, the next in order, and the staple combustible element in fuel,
has only a heating power of 14-3/4 pounds of water.