COAL AND COAL MINING. By coal is comprehended all the fossil fuels contained in the earth's crust. Being an amor phous substance of variable composition it cannot be as strictly defined as can a crystallized or definite mineral. Coal, strictly speaking, is not a mineral but a rock, and, further, it is a sedi mentary rock; the mineral substance, consisting mainly of com plex carbon compounds, is amorphous. There is no standard coal: there is an almost endless series of varieties, from brown coal at the one extreme to anthracite at the other; and even the brown and the anthracite vary greatly in character and composition as do all the coals coming between them. Peat is sometimes included under the term coal, but erroneously so, seeing it cannot be re garded as a fossil fuel.
The substance coal has been known in the common language of Britain from earliest historical times by specific names. That the ancient Britons in general were acquainted with coal as such is evident from its appellation at the present time, which is not Saxon but British, and subsists among the Irish as goal, amongst the Cornish in kolan and in Welsh as glo to this day. That the word kohle to designate coal was in general use in England before the Norman invasion is proved by the fact that the French (charbon) or Latin (carbo) name was not adopted. The deriva tion is referable to a pretty widely spread root signifying simply "black," e.g., the Arabic kaki, Turkish kdrci (thus Kara-on, the black water; Kara Denghoz, the Black Sea, etc.), the Greek KOtacvos, used by Homer for black. The spelling "tole" or "coalle" was generally used up to the middle of the 17th century, when it was gradually superseded by the modern form "coal." The word anthracite—a form of coal of high fixed carbon con tent—is from the GreekavOparctrris. About 371 B.C. Theophrastus, pupil of Aristotle, uses the word in his treatise "On Stones," where he mentions fossil substances "that are called coals, which kindle and burn like woodcoals." "These are found in Liguria and in Elis, in the way to Olympias, over the mountains ; they are used by the smiths." This is probably the earliest mention of true coal (not charcoal) on record. The term lithanthrax, stone coal, still survives, with the same meaning, in the Italian litantrace.
The first record of the use of coal in Great Britain is frequently stated to be in A.D. 852, when it is recorded in the Saxon Chronicle of the Abbey of Peterborough that the Abbot Ceobred let the land of Sempringham to Wulf red, who was to send each year to the monastery "6o loads of wood, 12 loads of coal, 6 loads of peat, etc." It is most probable, however, that the Romans were acquainted with the use of coal during their occupation of Britain from the fact that we find coal cinders among the ruins resisting parts of the plants into a compact mass.
It would certainly seem beyond dispute that these extremely microscopic organisms existed in carboniferous times, particularly in the case of some coprolites or fossilized excreta of Permo Carboniferous fish or reptiles, for in them Renault and Prof. Bertrand demonstrated the actual bacillus. But apart from actual identification of the bacteria, there appears almost conclusive evi dence to the effect that the tissues, included in the plant petri factions, exhibit all the indications of cells attacked and destroyed