The Young process was utilized with much success in the United States until such time as it became unprofitable owing to the largely increasing production in America of liquid oils obtained direct from the earth. It was about this time that a bituminous mineral known as Boghead coal, and existing in the Midlothians, was discovered, and from this Young secured upwards of 100 gallons of oil from each ton treated, but soon this mineral was, in a practical sense, exhausted, and so the bituminous shales, now known as oil-shales, came in for attention. Before passing away from Dr. Young’s services in connection with the establishment of the Scottish shale-oil industry, it should be mentioned that he figures very largely in more than one of the earlier Scottish shale concerns. He founded the Bathgate Oil Company, which, in the zenith of its operations, treated 1,000 tons of shale daily, this Company being later merged into the Young’s Paraffin Light and Mineral Oil Company, Ltd., one of the large Scottish shale-oil undertakings and well known throughout the world to-day. The Scottish shale-oil fields, as exploited to-day, cover a belt of territory which is about 6 miles broad and stretches from Dalmeny and Abercorn, on the Firth of Forth, southwards across the fertile tract between the River Almond and the Bathgate Hills to the moorland district of Cobbinshaw and Tarbrax. Throughout this region there are various important mining centres, such as Broxburn, Uphall, East Calder, Mid-Calder, West Calder, and Addiwell; and in connection with the shale-oil industry, upwards of 25,000 persons now find regular employment. The shale measures on which the shale-oil industry depends, form part of the calciferous sandstone series of Mid and West Lothian and the southern coast of Fife. The carboniferous system of Scotland may be arranged in descending order in four divisions, as under-- 4. Coal measures, comprising red sandstone, shales, and marls with no workable coals, underlaid by white and grey sandstones and shales with numerous valuable coal seams and ironstones. 3. Millstone grit, consisting of coarse sandstones, with beds of fireclay, a few thin coals, ironstones, and thin limestones. 2. Carboniferous limestone series, embracing three subdivisions, the highest of which contains three or more limestones with thick beds of sandstone and some coals, the middle includes several valuable seams of coal and ironstone, and the lowest is characterized by several beds of marine limestone with sandstone, shales, some coals, and ironstones. 1. Calciferous sandstone series, forming two subdivisions. The upper is known as the oil-shale group, and is over 3,000 feet in thickness, and contains, in its highest part, beds of coal, usually of inferior quality, and, farther down, about six main seams of oil-shale, inter-stratified with beds of sandstone, shale, fire-clay, marl, and estuarine limestones.