700 



SCIENCE. 



[N. S. Vol. XVII. No. 435. 



contained iron in a metallic or oxidized state'; 

 but no slightest response was shown under the 

 most powerful action of the machine, and 

 with diamonds of the most marked yellow and 

 dark tints. If they contain iron at all, its 

 amount must be infinitesimal. 



That the ' blue-ground ' is not a decom- 

 posed lava, and has not been greatly heated 

 since the diamonds have been in it, is shown 

 by experiments of Herr Luzi, at Leipsic (Ber. 

 d. Deutschen Cliem. Gesell., 1892), which are 

 here described, but which have not attracted 

 the attention that they deserve. He fused 

 some of the ' blue-ground ' in a graphite 

 crucible at 1770° R. (4014° F.) and then in- 

 troduced a diamond crystal, and closed and 

 reheated the crucible. The diamond, pre- 

 viously smooth and brilliant, was found to 

 have been corroded and etched, i. e., partially 

 dissolved, by the fused silicate mixture, in 

 which it had been originally embedded. Mr. 

 Williams then asks. How is it possible that 

 most of the crystals found are bright and 

 polished, with no trace of such corrosion, if 

 the blue-ground has ever been in any condi- 

 tion of fusion from heat, like a lava. 



The latest reference of the diamonds to an 

 origin in an eclogite rock at very great depths, 

 suggested by Professor Bonney, in conse- 

 quence of some having been found enclosed 

 in boulders of that rock in the blue-ground 

 of the Newland's mine, is duly considered, 

 and some questions raised in regard to it by 

 Professor Bonney himself are stated. Mr. 

 Williams expresses no positive opinion as to 

 this view, the facts observed at the ISTewland's 

 mine not having come under his notice at 

 De Beers or Kimberley; and, as before stated, 

 his latest word is non-committal. 



The next two chapters, on ' The Diamond 

 Market ' and ' Cutting and Polishing,' are 

 abundantly interesting, but can not be en- 

 larged upon in this sketch. Suffice it to say 

 that they are full and accurate accounts, 

 freely illustrated, of all the methods of as- 

 sorting and valuing the diamond-product, to- 

 gether with notes on the other diamond re- 

 gions of the world and on the sale and 

 distribution of the stones in commerce; and 

 in the eighteenth chapter, of the history and 



development of the art of cutting, and of 

 the present methods and principal seats of 

 the industry. 



The closing chapter, 'An Uplifting Power,' 

 is a remarkable presentation, from the Rhodes- 

 De Beers standpoint, of the influence of the 

 great diamond fields on the development, prog- 

 ress and civilization of the Dark Continent. 

 The opening of mines ; the building of cities ; 

 the laying out of railroads; the conversion of 

 an arid wilderness into a populous and pro- 

 gressive land of civilized institutions ; the 

 repression of bloody tribal warfare; and the 

 extension of British control and influence far 

 toward the equator, and ultimately, in vision, 

 ' from the Cape to Cairo ' — all these have re- 

 sulted largely from the Kimberley discoveries. 

 They were the dream and the ambition of Mr. 

 Rhodes, who bent all his truly wonderful ener- 

 gies toward their accomplishment, seeking 

 wealth and power, as Mr. Williams emphat- 

 ically contends, not as ends in themselves, 

 but as means to the realization of a grand 

 historical idea. The account is both impres- 

 sive and inspiring, and evidently contains a 

 large amount of truth. Of the other and 

 darker side, nothing is said ; the ' Jameson 

 raid' is not mentioned and the recent war is 

 but slightly alluded to, save in the account of 

 the siege, in the appendix, and then only in 

 its local incidents. It is but just to Mr. 

 Williams, however, to recall that he is writing 

 about the De Beers mines, and not about the 

 history of South Africa in general, though the 

 two are closely connected, as he himself has 

 shown. His estimate of Mr. Rhodes is ex- 

 ceedingly high and his sympathy with him is 

 profound, but he writes in a spirit of great 

 breadth and fairness that impresses the reader 

 very favorably. 



The volume closes with an appendix, of 

 which the first part is a history of the siege 

 of Kimberley. This is a most vivid and even 

 thrilling account of the four months' invest- 

 ment ; the conversion of the mine-workers into 

 a garrison, and of the tailing-heaps into re- 

 doubts; of the turning of all the machinery 

 and resources of the great mining plant into 

 one and another means of defense ; of the 

 ever-ready energy of Mr. Rhodes to meet new 



