l, which he used for burning
in lamps, whilst the heavier product which he also obtained proved a most
useful lubricant for machinery. This naturally distilled oil was soon
found to be similar to that oil which was noticed dripping from the roof
of a coal-mine. Judging that the coal, being under the influence of heat,
was the cause of the production of the oil, Mr Young tested this
conclusion by distilling the coal itself. Success attended his endeavour
thus to procure the oil, and indelibly Young stamped his name upon the
roll of famous men, whose industrial inventions have done so much towards
the accomplishment of the marvellous progress of the present century.
From the distillation he obtained the well-known Young's Paraffin Oil,
and the astonishing developments of the process which have taken place
since he obtained his patent in 1850, for the manufacture of oils and
solid paraffin, must have been a source of great satisfaction to him
before his death, which occurred in 1883.

Cannel coal, Boghead or Bathgate coal, and bituminous shales of various
qualities, have all been requisitioned for the production of oils, and
from these various sources the crude naphthas, which bear a variety of
names according to some peculiarity in their origin, or place of
occurrence, are obtained. Boghead coal, also known as "Torebanehill
mineral," gives Boghead naphtha, while the crude naphtha obtained from
shales is often quoted as shale-oil. In chemical composition these
naphthas are closely related to one another, and by fractional
distillation of them similar series of products are obtained as those we
have already seen as obtained from the crude coal-naphtha of coal-tar.

In the direct distillation of cannel-coal for the production of paraffin,
it is necessary that the perpendicular tubes or retorts into which the
coal is placed be heated only to a certain temperature, which is
considerably lower than that applied when the object is the production of
coal-gas. By this means nearly all the volatile matters pass over in the
form of condensible vapours, and the crude oils are at once formed, from
whence are obtained at different temperatures various volatile ethers,
benzene, and artificial turpentine oil or petroleum spirit. After these,
the well-known safety-burning paraffin oil follows, but it is essential
that the previous three volatile products be completely cleared first,
since, mixed with air, they form highly dangerous explos