112 Canadiafi Record of Science. 



percentage of silica (itacolumite, granite, etc.) has been 

 asserted, the statement needs corroboration. This form 

 of crystallised carbon, hitherto has been found only in 

 meteoric iron (Canyon Diablo), and has been produced 

 artificially by Moissan and others with the same metal as 

 matrix. But in eclogite the silica percentage is at least 

 as high as in dolerite; hence it is difficult to understand 

 how so small an amount of carbon escaped oxidation. 

 I had always expected that a peridotite (as supposed by 

 Professor Lewis^, if not a material yet more basic, would 

 prove to be the birth-place of the diamond. Can it 

 possibly be a derivative mineral, even in the eclogite ? 

 Had it already crystallised out of a more basic magma,'^ 

 which, however, was still molten, when one more acid 

 was injected, and the mixture became such as to form 

 eclogite ? But I content myself with indicating a diffi- 

 culty, and suggesting a possibility ; the fact itself is 

 indisputable : that tJie diamond occurs, though rather 

 sporadically, as a constituent of an eclogite, which rock, 

 according to the ordinary rules of inference, must be 

 regarded as its birth-place. 



This discovery closes another controversy, viz.: that 

 concerning the nature of the " Hard blue " of the miners 

 (Kind^erlite of Professor Lewis), in which the diamond is 

 usually found. The boulders described in this paper are 

 truly water worn. The idea that they have been rounded 

 by a sort of " cup and ball " game played by a volcano 

 may be dismissed as practically impossible. Any such 

 process would take a long time, but the absence of true 

 scoria implies that the explosive phase was a brief one. 

 They resemble stones which have travelled for several 

 miles down a mountain torrent, and must have been 

 derived from a coarse conglomerate, manufactured by 

 either a strong stream or the waves of a sea from frag- 



1 Tliis, liowevcr, cuuiiot liavn been very i-ii_:li in iron, bucause iliopsicle does not. 

 fiiutain much of Uiut constituent. 



