346 



NATURE 



[January 3, 19 18 



sylvine contained about 98,000,000 cubic metres, 

 distributed over 84,000,000 square metres, whereas 

 the lower layer amounted to 603,000,000 cubic 

 metres, spread over an area of 172,000,000 

 square metres, equivalent in round numbers to 

 1,500,000,000 tons of potassium salts, or 

 300,000,000 tons of pure potash. The first 

 boring's were made at Wittelsheim (originally in 

 1904, in searching for coal), and some fourteen 

 others have been made over different parts of the 

 area. The salt began to be won in 1910, and in 

 191 2, from the Amelia mine, with 200 men, the 

 daily output reached 300 tons. The mineral, 

 brought to bank, was crushed and powdered and 

 either treated directly for the manufacture of 

 " muriate " or exported. 



The potash layers are composed of bands, alter- 

 nately red and grey, consisting principally of a 

 mixture of sylvine and rock-salt. The red bands, 

 coloured with ferric oxide, contain the principal 

 amount of the potash salt, whereas the grey con- 

 sist mainly of common salt. In addition there are 

 found thin layers of argillaceous schist and 

 anhydrite. The content of potassium chloride 

 varies from 20 to 68 per cent., and rarely falls as 

 low as 10 per cent. The raw products contain only 

 insignificant quantities of magnesium salts and 

 may, therefore, be used directly in agriculture after 

 grinding. In this respect they are more advan- 

 t^eous than tHe Stassfurt salts, which need 

 separation from the large quantities of associated 

 magnesium salts. The Reichweiler factory is 

 capable of treating daily about 260 tons of the raw 

 mineral, producing from 40 to 50 tons of pure 

 potassium chloride. The content of bromine is 

 so small as not to be worth extraction. 



The production of Alsatian potash is carefully 

 regulated by the German Government, and by the 

 law of May 25, 1910, the Amelia mine, the only 

 one actually at work in Alsace, was allowed to pro- 

 duce no more than 1*46 per cent, of the total yield 

 of the Empire, i.e. 9000 tons of pure potash, or 

 45,000 tons of raw salt, corresponding with an ex- 

 traction of fifteen wagons per diem, far below what 

 it was capable of affording. At the beginning of 

 the war, in spite of some improvement in the situa- 

 tion, the fifteen Alsatian mines, capable of yielding 

 in the aggregate about 800,000 tons per annum, 

 were allowed to sell only 80,000 tons, and the total 

 amount reserved to Alsace was permitted to be 

 only about one-tenth of the. German production. 

 This action is, of course, due to the attempts 

 of the German authorities to control and 

 strengthen the monopoly they practically possess — 

 ai condition which would be altogether modified by 

 the return of Alsace to France, and by the rdle 

 which the State mines of Stassfurt might be made 

 to play in the case of a war indemnity by Germany. 



Of the other considerable natural deposits which 

 are known to occur, the most important are those 

 of Spain and Abyssinia. The Spanish beds occur 

 at Suria, in Catalonia, and to-day belonef to the 

 Solvay Company. They have been found at 

 depths of from 40 m. to 60 m., but certainly extend 

 much deeper. They date probably from the end of 

 NO. 2514, VOL. 100] 



the Eocene or the beginning of the Oligocene 

 period and are widely distributed, the potash salts 

 occurring irregularly mixed with rock-salt. The 

 potash compounds consist of carnallite and sylvine 

 in layers of an intense red colour, with alternate 

 reddish layers of common salt. The richest zones 

 appear to follow anticlinal folds running from south 

 to north to Cardona, Suria, and Callus. The area 

 explored is only some 230,000 square metres, but it 

 is said to contain about two and a half million tons 

 of carnallite and nearly a million and a quarter tons 

 of sylvine in local thicknesses of 17 m. of car- 

 nallite and 3'75 m. of sylvine. At present these 

 Spanish deposits are not utilised, owing to the 

 influence of Germany on Spanish affairs. The 

 Cortes was offered a Bill in order to promote the 

 working of the mines, but it was opposed by a 

 faction in the interests of Germany, and no result 

 followed. A Royal decree in June, 191 5, modified 

 the conditions, but these were still so restrictive 

 that the Solvay Company was prevented from ex- 

 ploiting the mines. On the other hand, certain 

 Spanish corporations, working in concert with the 

 German syndicate' at Stassfurt, have obtained con- 

 cessions in the vicinity of Cardona, and State 

 reservations have been created in the provinces of 

 Barcelona and Lerida ; but no further action has 

 been taken, ostensibly on the ground that the 

 Spanish Geological Institute has not yet completed 

 its explorations. 



The Abyssinian deposits belong to Italy. They 

 occur in Erythrea, at 90 km. from the coast to the 

 south-east of Massaoua, and at 10 km. to the north 

 of Atel Bad in long. 40°, close to the Italian frontier. 

 Their exploitation has hitherto been very difficult, 

 owing to tKe hostility of the Abyssinians. These 

 conditions are now notably improved, partly by a 

 more effective possession by the Italians, and 

 partly by recent changes in the Government of 

 Abyssinia, which is more favourably disposed 

 towards the Allies. The deposits already 

 furnish about 20,000 tons per annum. Not 

 much is known concerning their physical char- 

 acteristics or the conditions of their formation, 

 but they are certainly much more recent than those 

 of Alsace and Spain, which are Tertiary ; they have 

 probably been formed by the comparatively recent 

 evaporation of an ancient arm of the sea running 

 north and south, due to one of the great lines of 

 rupture extending- frohi Palestine and traversing 

 the whole of the east of Africa along a region still 

 of volcanic activity. 



Conditions such as probably have produced the 

 Stassfurt deposits are still at work and may be 

 observed in several parts of the world operating 

 over large areas, as, for example, in the Adji- 

 Darja Bay, in the east of the Caspian Sea — a bay 

 2000 to 3000 square miles in extent, and almost 

 entirely shut off from the Caspian by a bar. There 

 is here a continuous separation of salt, estimated 

 by Schleiden to be about 400,000 tons per diem, 

 with an outflow of dense mother-liquor back to the 

 Caspian, except where it sinks in the deeper parts 

 of the bay, when the mother-liquor salts are 

 gradually deposited. None of these areas has 



