Nitrogen is also an elementary body. It neither supports life nor combustion; it is lighter than air and has no taste or smell. One cubic foot at 32° temperature weighs a trifle less than one ounce.
Sulphur is also an elementary body, of a yellow color, brittle, does not dissolve in water, is easily melted, and inflammable. It is also called brimstone or burnstone, from its great combustibility. It burns with a blue flame, and with a peculiar, suffocating odor.
Carbonic Acid Gas is formed by the burning of sixteen parts of oxygen and six parts of carbon. Its specific gravity is 1.529; it is fatal to life, and it also extinguishes fire.
Carbonic Oxide is a colorless, transparent, combustible gas, which burns with a pale blue flame, as may be seen at times on opening a locomotive fire-box door. Its presence in a furnace is evidence of imperfect combustion from a deficient supply of air, as it indicates that only eight parts of oxygen instead of sixteen parts have united with six parts of carbon.
Table.
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 641⁄4 pounds of water, whilst carbon, the next in order, and the staple combustible element in fuel, has only a heating power of 143⁄4 pounds of water.