TRANSACTIONS OF SOCIETIES. 63I 



liitherto unknown in Africa, has recently been reported from South Africa. 

 The author pointed out that the best known South African truffles belong 

 to the genus Terfccia. The distinction between the two genera was indi- 

 cated, and a description given of a truttie, T. Clavcryi cliat., recently sent 

 to the author from the Gri([ua'and West district in the Kalahari. 



Chemical, METAu.t'KOicAL, and Mining Society of South Africa. — 

 Saturday, June 2,3rd : Prof. J. .\. Wilkinson. M.A., F.C.S., President, in 

 the chair. — "The construction and maintenance of slime dams": J. E. 

 Thomas and E. A. Osterloh. Slime dams have generally to be built 

 from the slime itself, and so the most that can be attempted is to make the 

 outside walls of suitable tiiickness, avoiding excess of moisture in con- 

 struction. How this may be effected the authors proceeded to explain in 

 detail. — "' Some notes on explosioons of firedamp and occurrences of gob 

 fires in Natal " : J. E. Yaughan and F. A. Steart. An account of the 

 history of colliery explosions in Xatal was given and concluded with a 

 number of preventive recommendations. Amongst these were extraction 

 of the top seam, retention of as little timber and coal as possible in the goaf, 

 measures for complete isolation of any section where the temperature rise* 

 above 70 degrees, and also when the odour of benzene appears. 



