PRESIDENTIAL ADDRESS — SECTION B. 63 



also been discovered on the property of the Randfontein Central 

 Gold Mining Company. 



Mica. 



The pegmatites of the so-called Mica Belt, in theLeydsdorp 

 division of the Transvaal, yield muscoviate mica of excellent 

 quality, of which there is a small but steady production. Efforts 

 are being made to establish an export trade in the mineral, 

 which is in great demand at the present time for aeroplanes and 

 the condensers of wireless stations. Limited quantities are used 

 in South Africa for electrical purposes, and there is a small mica 

 factory in Johannesburg, where mica lamp-chimneys, stove-fronts, 

 and micanite sheets are made.* 



Soda. 



The soda production of the Union, amounting m 1917 to 

 5,674.75 tons, value at £29,192 is derived from the remarkable 

 salt-panf on the farm Zoutpan, 25 miles north-west of Pretoria. 



Hitherto operations have practically been confined to thin 

 layers of nearly pure trona, but enormous quantities of soda are 

 also available in the mud underlying and interbedded with the 

 trona layers. This has been proved to a depth of over 200 feet, 

 and averages about 15 per cent, of NaoCog. A plant for the 

 preparation of pure soda from the mud is at present being erected, 

 and if it proves successful the future of the industry will be 

 assured for many years to come. 



Talc. 



Almost the whole of the talc production of the Union comes 

 from the Verdite Mine, near Noordkaap Station, in the Barberton 

 district of the Transvaal, "in the neighbourhood of which there 

 are other considerable deposits. There is also a small production 

 in the Krugersdorp district of the Transvaal, and in Zululand. 



The talc of the Barberton district deposits has been proved 

 to be well adapted to the manufacture of paper and rubber. As 

 it can be cheaply mined, and the railage to Delagoa Bay is only 

 3s. 6d. per ton, it is confidently anticipated that a large export 

 trade in it will be established after the war.* 



Tungsten. 



The small output of tungsten recorded in the table of mineral 

 production comes from the Stavoren Tin Mine, in the Olifants 

 River tin-fields. Several tons of scheelite were also recovered 

 in 1917 from a deposit in the neighbourhood of Leydsdorp, but 

 this is not being worked at the present time. 



* Cf. Wagner, P. A. : S.A. Journ. Industries, April, 1918. 

 t For a description and plan of the Salt Pan see Wagner, P. A. : Proc. 

 Geol. Soc. S.A. (1917), 30-38. 



t S.A. Journ. Industries, June, 19 18. 



