coal region at night could see through his car window the flames of
hundreds of old-fashioned bee-hive coke-ovens and if he were of
economical mind he might reflect that this display of fireworks was
costing the country $75,000,000 a year besides consuming the
irreplaceable fuel supply of the future. But since the gas was not
needed outside of the cities and since the coal tar, if it could be sold
at all, brought only a cent or two a gallon, how could the coke-makers
be expected to throw out their old bee-hive ovens and put in the
expensive retorts and towers necessary to the recovery of the
by-products? But within the last ten years the by-product ovens have
come into use and now nearly half our coke is made in them.

Although the products of destructive distillation vary within wide
limits, yet the following table may serve to give an approximate idea of
what may be got from a ton of soft coal:

1 ton of coal may give
Gas, 12,000 cubic feet
Liquor (Washings) ammonium sulfate (7-25 pounds)
Tar (120 pounds) benzene (10-20 pounds)
toluene (3 pounds)
xylene (1-1/2 pounds)
phenol (1/2 pound)
naphthalene (3/8 pound)
anthracene (1/4 pound)
pitch (80 pounds)
Coke (1200-1500 pounds)

When the tar is redistilled we get, among other things, the ten "crudes"
which are fundamental material for making dyes. Their names are: