Dr. A. Holmes — Non-German Sources of Potash. 343 



Abyssinians are very jealous of the economic invasion of their 

 territory. 



The Dellol deposit itself is now definitely known to be within 

 Abyssinia, though it is worked by an Italian Syndicate under con- 

 cession from the Abyssinian Government. Conditions of labour are 

 far from pleasant, as the region is one of extreme aridity, while the 

 average temperature in the shade is over 120° F. Nevertheless, in 

 spite of climatic difficulties, there were atone time nearly 8,000 men 

 employed in mining the potash, making a road to the coast, and 

 building a port at Fatiruari, a tiny settlement on the Bay of Haoachil, 

 46 miles to the north of Dellol. 1 Early in 1917 arrangements were 

 made for constructing a light railway to Eatiniari, and by now this 

 should have taken the place of camel transport, for at the end of last 

 year the track was rapidly approaching completion. 



For many of the details made use of in the above description I am 

 indebted to Captain Cockerell, the Controller of the Department of 

 Mineral Resources Development of the Ministry of Munitions, and to 

 Mr. Henry C. D. Blattner, who spent some months in examining the 

 deposit during the early stages of its commercial development. 



Natural Brines. 



Since potassium salts are among the most soluble of the saline 

 materials contained in natural waters, they become gradually 

 concentrated as evaporation proceeds, and are finally deposited from 

 the brines that lie over the crystalline body already deposited, or from 

 the mother-liquors that occupy its pores. In various arid regions 

 there are more or less desiccated lakes from which potash-rich brines 

 are extracted ; notably in the United States and Tunis. Here also 

 the salt-marsh of Salin-de-Giraud in the delta of the Rhone may be 

 mentioned, though the output of KC1 derived from the evaporation 

 of its waters is comparatively small. 



SearWs Lake. — The deposit to which this nam e is applied occurs in 

 a depressed and elongated basin-like region in the north-eastern 

 corner of San Bernadina County, California. 2 During the Glacial 

 epoch the basin, which is nearly surrounded by abruptly rising hills, 

 was occupied by a lake whose surface stood 640 feet above the level 

 of the present floor. A firm but very porous sheet of white salts now 

 lies exposed over an area of 12 square miles, and laterally the 

 deposit extends still further beneath the surrounding mud-flats. 

 Down to a considerable depth rock-salt is the chief mineral found, 

 but below 12 to 20 feet from the surface irregular layers are found 

 rich in trona or thenardite, and rarely in sylvinite. The deposits 

 have provided a rich suite of minerals, the genetic study of which, as 

 yet scarcely begun, will rival in interest that of the Stassfurt salts. 



Except quite near the surface, the interstices of the crystal 

 aggregates — amounting to 40 per cent by volume — are occupied by 

 a highly concentrated brine, and from this the American Trona 

 Corporation extracts a number of salts, including KC1. The brine, 

 which has the composition set forth in the table below, is known to 



1 African World, August 18, 1917. 



2 A. de Ropp, Journ. Ind. & Eng. Chem., vol. x, p. 839, 1918. 



