Resume of Recent Scientific Publication*. 463 



de Launay, L. " Les Diamants du Cap." 8vo, pp. vii and 226, 

 Paris, Librairie Poly technique, Baudry & Cie., 1897. 



This is an account of Cape Diamond Mining under the 

 following heads : — 



History and actual commercial organisation of the Cape 

 diamond industry ; the geology of the deposits ; the method 

 of working ; the methods of treatment ; working personnel : 

 comparison of the Cape with other diamond regions, and 

 a final section on the origin of the Cape diamonds and the 

 synthesis of the diamond. 



The first section gives the statistics of the Cape diamond 

 industry since 1867 and a short table of the total production 

 of diamonds in the world, and estimates that in 1897 the actual 

 number of diamonds in the world would be the cut equivalent 

 of 79,000,000 carats of rough diamonds. The gradual rise and 

 development of the De Beers Company is given as well as the 

 existing arrangements for the sale of the stones found, and 

 the section concludes with statistics about Jagersfontein and 

 the less prominent mines. 



The chapter dealing with the geology of the deposits gives 

 a historical account of the diverse opinions held as to the nature 

 of the containing rock and the view that the serpentine-breccia 

 filling the pipes has brought the diamonds from below is stated 

 by Prof, de Launay to be now indisputable. An account of the 

 basic igneous rocks associated with the " blue ground," which 

 is also described in some detail, a list of the minerals occurring 

 in the breccia with the diamond, as well as an account of the 

 largest diamonds yet found, sums up the main contents of the 

 final part of this chapter. The age of the pipes is given as 

 being slightly subsequent to the Trias. 



The next three sections present in detail the methods employed 

 in working the various mines and are illustrated by photographs 

 and diagrams. 



Chapter vi. deals largely with the Brazil diamond deposits, 

 and also those of India, Borneo, and Australia. Diamonds were 

 discovered in auriferous sands in Brazil in 1727. The chief 

 centres are the provinces of Minas-Geraes and Bahia. The 

 deposits are nearly all alluvial and are of three kinds : (1) Eiver 

 deposits ; (2) river-terrace deposits ; (3) plateau deposits which 

 often cover a diamantiferous conglomerate. 



The Indian deposits which have been worked since, probably 



