distillation in the earth; i.e. the gases have mostly been driven
off. It is much used in New England.

48. Bituminous, or soft coal, crocks the hands, and burns rapidly
with much flame and smoke. The greater part of the coal in the
earth is bituminous. It represents incomplete distillation.
Hence, by artificially distilling it, illuminating gas is made.
See page 180. It is far less pure C than anthracite.

49. Cannel Coal is a variety of bituminous coal which can be
ignited like a candle. This is because so many of the gases are
still left, and it shows cannel to be less pure C than bituminous
coal.

50. Lignite, Peat, Turf, etc., are still less pure varieties of
C. Construct a table of the naturally occurring forms of this
element, in the order of their purity. Carbon forms the basis of
all vegetable and animal life; it is found in many rocks, mineral
oils, asphaltum, natural gas, and in the air as CO2.

51. C a Reducing Agent.

Experiment 31.--Put into a small ignition-tube a mixture of 4 or
5 g. of powdered copper oxide (CuO), with half its bulk of
powdered charcoal. Heat strongly for ten or fifteen minutes.
Examine the contents for metallic copper. With which element of
CuO has C united? The reaction may be written: Cu0 + C = CO + Cu.
Complete and explain.

A Reducing, or Deoxidizing, Agent is a substance which takes away