62 PRESIDENTIAL ADDRESS SECTION V.. 



impossible to dispose of the concentrate at a remunerative price 

 owing to the fact that, at that time, smelters in the United 

 Kingdom and the United States, had more ore than they could 

 deal with. x\bout 200 tons of concentrate, averaging 50 per cent, 

 of zinc, were produced. 



Arsenic. 



Within the past six months a promising start has been made 

 to produce white arsenic locally, this material being extensively 

 used in the manufacture of arsenite of soda for sheep and cattle 

 dips, insecticides, and the like. The output for the first four 

 months of 1918, amounting to 6.185 tons, valued at £619, came 

 from the Stavoren Tin Mine, where massive arsenopyrite occurs, 

 together with cassiterite, scheelite, copper pyrite, and other 

 minerals. 



A plant for the production of white arsenic is also being 

 erected at the Consort Mine in the Barberton district. Here 

 arsenopyrite is associated with gold. 



As some £80,000 worth of arsenite of soda is annually con- 

 sumed in the Union, the prospects of the industry appear very 

 hopeful. 



Magnesite. 



The Union has considerable resources of magnesite, but 

 owing to the low price of the mineral it is at present only being 

 worked at Budd's Mine, near Malelane, in the Barberton district. 

 The output of the mine amounted in 1917 to 781 short tons, 

 valued at £2,050. 



The production of magnesite may be expected to increase 

 with the expansion of the local steel industry, but there is little 

 prospect of estabHshing an export trade in it.* 



Manganese. 



The manganese output, recorded in the table for 191 7, came 

 ];art]y ifrom a vein deposit in the Magaliesberg quartzite, near 

 Derdepoort. and partly from an occurrence which is being ex- 

 ploited on the farni Daniels Rust, 12 miles north of Krugersdorp. 



Here the manganese occurs as nodules, up to 12 inches in 

 diameter, composed of a mixture of pyrolusite and psilomelane. 

 These are scattered indiscriminately through residual clay, 

 resulting from the weathering of the dolomite of the Transvaal 

 system. The nodules average about 47 per cent, of metallic 

 manganese. The deposits appear to be of considerable extent, 

 and can be cheaply worked. 



A somewhat similar occurrence is being opened up at Rand 

 Gate, near Randfontein. At this locality, however, the man- 

 ganese content of the nodules is lower than on Daniels Rust. 



Within the last week a promising deposit of this nature has 



* Cf. Wagner, P. A.: S.A. Joiirii. [)idusfries. March. 1918. 



