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what was sometimes called the best coal was anthracite. The 
diamond was the only pure form of carbon, but anthracite con- 
tained as much as ninety percent. of carbon. It was interesting 
to know that any of the other kinds of coal might pass into 
anthracite by a natural process. ‘Chat process seemed to be con- 
nected with heat, not the direct burning heat, but that of the 
pressure of other strata, whether lateral or otherwise. Under 
such conditions coal became anthracitic, and where distillation 
had gone on, petroleum was produced. One of the valuable 
qualities about anthracitic coal was that it gave off no smoke 
during combustion, owing to its being devoid of a hydro-carbon. 
It also produced greater heat, and hence its use in the Navy and 
for the production of steam. Other kinds of coal were often sold 
as smokeless coal; these were not really anthracitic coal but mud 
coal, which had very little heat-producing qualities, and left an 
enormous quantity of ash. After briefly touching upon the 
character of other coals, in the course of which he alluded to the 
gaseous characteristics of cannel coal, Professor Jones went on to 
speak upon the formation of the coal deposits. The period of 
coal formation, he said, was in all probability a very luxuriant 
age, the areas being covered with jungles, interwoven with a 
dense undergrowth. From time to time square miles of these 
jungles would be swept down by a tornado, or by other causes 
snd in course of time the fallen masses of vegetation would be 
inundated,either by storm or by the rising and falling of the land 
There, under the water, the trees decomposed and changed into 
that black shiny substance now to be found in the peat bogs in 
Treland. Chemical changes went on, until what was wood 
became coal. Sometimes, however, the branches and parts of 
the trunks of the trees remained up out of the water, whereupon 
they did not undergo the chemical changes of the submerged 
parts, but rotted away down to the level of the water, and 
became mere rotten touchwood. and in some cases the markings 
of these trees could be seen in the shales that came from the 
neighbouring beds. As an indisputable proof of the fact that 
coal was formed of trees in this way, Professor Jones mentioned 
instances in which the wood had become calcified before it had 
turned into coal, and in such instances the structure of the trees 
and ferns was clearly traceable. In Scotland a volcanic eruption 
had come down on a coal field in the course of formation, and, very 
much after the style of what happened at Pompeii, the lava sealed 
up the materials of which the coal was being formed, and arrested 
further progress, so that microscopists of the present day could 
