5_' TRANSACTIONS OF SOCIETIES. 



dwelling-places, their use of snake, spider and plant poisons for their 

 arrows, their practice of witchcraft, and their views regarding resurrection 

 and transmigration.—" Note concerning the physical significance of the 

 mean diurnal curve of temperature" : Dr. J. R. Sutton. The author dis- 

 cussed the question whether hourly average temperatures have any great 

 scientific value, and concluded that, at Kimherley, the mean diurnal curve 

 of temperature is possibly made up of three superimposed curves of the 

 same period, proper to various outstanding types of weather. — " Note on 

 the earthquakes of the South African table-land " : Dr. J. R. Sutton. 

 In connection with the occurrence of four earthquake shocks felt since the 

 establishment of the observatory at Kenilworth (Kimberley), the author 

 calls attention to fluctuations of barometric pressure in progress at the 

 time of the shocks. 



South African Society of Civil Engineers. — Wednesday, July ioth: 

 Mr. A. D. Tudhope, M.I.C.K., President, in the chair.— " Watershed sta- 

 tistics of the Wemmers Valley" : R. W. Menmuir. The available yield of 

 the watershed was calculated at 53 million gallons per day. The rainfall 

 in the catchment area was estimated to have been, in 1904, 85 million 

 gallons per day, in 1905, 69 millions, in T906, 52 millions, in 1907, 66 millions, 

 and in 1908, 59 millions. 



Chemical, Metallurgical -\ni> Mining Society of South Africa. — 

 Saturday, April 20th: Mr. W. R. Dowling. M.I.M.M., Vice-President, in 

 the chair. — "The action of mineral sulphates and arsenates on cyanide 

 solutions'": A. F. Crosse. As the sulphates of magnesia and lime de- 

 compose cyanide solutions, the ordinary analysis of a mineral or ore to be 

 treated by the cyanide process is nearly valueless to the cyanide manager, 

 who needs to know what will take place when the finely-crushed ore 

 comes in contact with the cyanide solution. In many instances such 

 analyses do not show the presence of magnesium sidphate, although mag- 

 nesia may be incidentally mentioned. When a finely-ground ore containing 

 ,scorodite (ferric arsenate) is left in contact with a cyanide solution, a 

 decomposition of the latter also occurs. In such event the solution becomes 

 charged with arsenates, and the precipitated gold carries arsenic, which, 

 under sulphuric acid treatment, causes evolution of poisonous arseniuretted 

 hydrogen. The author proposed to overcome the injurious action of 

 arsenates on cyanide solutions by adding excess of lime and a small 

 quantity of sodium hydrate. All the arsenic would thus be precipitated 

 as calcium arsenate 



Saturday. May'i8th: Mr. W. R. Dowling, M.I.M.M., Vice-President, 

 in the chair. — "Note on dust determination by filtration through sugar" : 

 A. McA. Johnston. The air is drawn through a 2-in. layer of coarsely- 

 crushed loaf-sugar (from which everything finer than .006 in. has been 

 sifted away ) charged into a 25 c.c. glass separator and slightly moistened. 

 The dust is estimated by dissolving the sugar in distilled water and filter- 

 ing. — "New apparatus for sampling air for dust" : E. J. Laschinger 

 The author described the apparatus designed by him, at the request of 

 the Ventilation Sub-committee of the Miners' Phthisis Prevention Com- 

 mittee, in order to facilitate the rapid collection of air for the determination 

 of dust held in suspension. — " A. system of keeping underground costs and 

 records": G. H. Smith. Under existing conditions it is generally impos- 

 sible to form a correct estimate of the cost of doing any piece of work 

 needed underground, and hence to choose the cheapest and best method of 

 doing such work. The author, therefore, described in detail the system 

 adopted at the Ferreira Gold Mine for keeping underground costs in such 

 a way that they may be of practical use, and whereby it is possible to keep 

 in touch with the cost of all work going on by means of tabulated cost 

 sheets and graphic records. 



Saturday. June 22nd: Lt.-Col. C. B. Saner, M.I.M.M., A.I.M.E., Pre- 

 sident, in the chair. — "The surface workers on the Rand, and their tech- 

 nical education " : E. J. Pooler. The need was emphasised of having 

 white nun. technically trained, in charge of surface work on the mines. 

 There was a supply available of fairly well educated youths for such a 



