AND OTHER VARIETIES OF COAL. 107 



geological and chemical relations; for it is mj firm conviction, 

 that if the geological, chemical, and microscopical characters 

 of such substances do not mutually illustrate and confirm 

 each other, the truth has not been arrived at. 



It is my chief object to bring forward a number of facts, 

 which I have arrived at after a prolonged investigation, and 

 to detail the method which I have followed in such a way as 

 to enable every reader to repeat my observations, and either 

 to confirm or disprove them. 



I have taken tlie gi'eatest care to obtain authentic speci- 

 mens, if possible, from different sources, and I have examined 

 none of the perfect authenticity of which I had not the most 

 certain evidence, I have carefully examined com2)lete sec- 

 tions of the beds of coal of most importance in the inquiry, 

 I have broken up these masses, and examined the beds with 

 the naked eye from top to bottom. In the case of the Tor- 

 banehill coal I have made thin sections horizontally, and in 

 two directions vertically, at distances of a few inches thiough 

 the thickness of the bed, to determine the structure of the 

 whole ; and I have likewise examined the coals when reduced 

 to powder and coke. I have examined upwards of 200 sec- 

 tions, and other microscopical preparations of different coals, 

 of which 180 were prepared by my own hand from speci- 

 mens, the perfect authenticity of which I can easily prove. 

 In the whole examination I have endeavoured to make out 

 every fact as it presented itself, and to adopt no explanation 

 not consistent with the whole, and with the evidence derived 

 from every means of observation. Yet I have no wish that 

 anything which I may advance should be taken for granted. 

 I am prepared to prove every statement of facts by the pre- 

 parations on which my observations were made. 



The Torbanehill coal, which has recently excited so much 

 attention, owing to the well-known jury trial, Gillespie v. 

 Russel, is found in the coal-measures of the lands of Tor- 

 banehill, in the parish of Bathgate, county Linlithgow. It 

 forms a bed, varying in thickness from 1 foot 4 inches to 

 1 foot 11 inches, becoming darker in colour, coarser in tex- 

 ture, and less valuable as a gas coal, at Bathvale, on the west 

 of the lands of Boghead ; and very much coarser, and less 

 valuable still, at Barbachlaw, about half a mile to the north- 

 west of Boghead, where the seam is worked by the Monk- 

 land's Iron Company. 



The position of the bed does not differ from that of a bed 

 of coal. It has a thin layer of cement-stone immediately 

 above it, varying in thickness from half an inch to two inches. 



