The refining of the crude platinum has been, and still is, almost entirely in foreign hands, all but approximately 2 per cent. of the entire output being refined abroad. In 1915 it was reported that the construction of a refinery at Ekaterinburg was completed, which was to be placed under Government control. The principal platinum-refining works were formerly those of Johnson, Matthey & Co., Ltd., of England, but early in the eighties this firm was, to a certain extent, superseded by Heraeus & Co., of Hanau, Germany. They, in turn, in 1909, were compelled to give first place to the Société Anonyme de l’Industrie du Platine, of Paris, which became the chief centre of the platinum-refining industry, a position which it held until the outbreak of war. France at that time had a monopoly of 90 per cent. of the Russian production. This foreign control had an unfavourable effect on the industry, and in 1913 the Russian Government passed a law forbidding the exportation of crude platinum. In July 1915, exportation was again permitted, subject to a 30 per cent. _ad valorem_ export tax, and at about the same time an order was issued forbidding the exportation of raw platinum in quantities valued above 500 roubles (£53), the price of the metal to be fixed by the State[15] p. 923. In February 1917 the Government further enacted an order prohibiting the importation of drawn and spun platinum. It was hoped by these means to encourage the establishment of domestic refineries. In 1916 the Government fixed the price at £16 10s. per oz. In March 1917 it was reported that the miners were not satisfied, and later sales were reported up to £22 per oz. of crude metal, 83 per cent. fine[50] p. 17. According to N. Vissotzki[51], the platiniferous belt of the Urals, geologically speaking, consists of four parallel bands striking, roughly, north and south; the westernmost of these, made up of crystalline schists, forms the watershed between Europe and Asia. The next band to the east comprises olivine- and mica-gabbros, diallage-peridotites, diorites and altered syenites—all of which have been erupted from a great depth. The third band is made up of Lower Devonian sedimentary rocks, shattered and buried in places by diabasic eruptive rocks. The eastern portion of this band is formed of eruptive rocks of deep-seated origin which may be gneissose granites. The fourth, or most easterly band, is composed of ancient rocks, which have been eroded by the advancing sea of Lower Tertiary age. The area emerged from the waves as early as the Carboniferous period; consequently the accumulation of platinum, and in some localities of gold, in the surface-deposits, were not swept away. They were concentrated later on in the alluvia—perhaps at the time of the most intense glaciation, probably in the Pleistocene.