DIAMONDS/ 



By William Crookes, F. E. S. 



It seems but the other day I saw Loudon iu a blaze of illumiuatiou to 

 celebrate Her Majesty's happy accession to the throne. As iu a few 

 days the whole Empire will be celebrating the Diamond Jubilee of our 

 Queeu, who will then have reigned over her multitudinous subjects for 

 sixty years, what more suitable topic can I bring before you than that 

 of diamonds? One often hears the question asked: "Why Diamond 

 Jubilee?" I suppose it is a symbol intended to give a faint notion of 

 the pure brilliancy and durability of the Queen's reign; and in thus 

 associating Her Majesty with the precious diamond, to convey an idea 

 of those noble qualities, public and i)rivate, which have earned for her 

 the love, fealty, and reverence of her subjects. 



From the earliest times the diamond has occupied men's minds. It 

 has been a perennial puzzle — one of the riddles of creation. The phi- 

 losopher Steftaus is accredited with the dictum that "Diamond is 

 quartz which has arrived at self-consciousness;" and an eminent 

 geologist has parodied this metaphysical definition, saying, "Quartz is 

 diamond which has become insane." 



Professor Maskelyne, in a lecture "On diamonds," thirty-seven years 

 ago, in this very theater, said: "The diamond is a subst.ince which 

 transcends all others in certain properties to which it is indebted for its 

 usefulness in the arts and its beauty as an ornament. Thus, on the one 

 hand, it is the hardest substance found in nature or fashioned by art. 

 Its reflecting power and refractive energy, on the other hand, exceed 

 those of all other colorless bodies, while it yields to none in the perfec- 

 tion of its pellucidity;" but he was constrained to add, "The formation 

 oi the diamond is an unsolved problem." 



Recently the subject has attracted many men of science. The devel- 

 opment of electricity, with the introduction of the electric furnace, has 

 facilitated research, and I think I am justified in saying that if the dia- 

 mond problem is not actually solved, it is certainly no longer insoluble. 



GRAPHITE. 



Intermediate between soft carbon and diamond come the graphites. 

 The name graphite is given to a variety of carbon, generally crystal- 

 line, which in an oxidizing mixture of chlorate of potassium and nitric 



^ A lecture delivered at the Royal Institution, June 11, 1897, by William Crookes, 

 F. R. S. Printed in Nature, No. 1449, vol. 56, August 5, 1897. 



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