SCIENCE-GOSSIP. 



203 



success, encouraging, if not complete, has been 

 achieved. Though the hope of the alchemists of 

 transmitting the baser metals into gold, and thus 

 of discovering, in the exercise of the chemical art, 

 a short cut to wealth, seems destined never to be 

 realised, it is probable that the production of true 

 diamonds in the laboratory of the chemist would 

 seem to the alchemists at least equally marvellous. 

 From an observation of the sudden increase of 

 volume which the diamond undergoes at a high 

 temperature, it was concluded that it was probably 

 a form of carbon which had been subjected to 

 great pressure when crystallizing. Pursuing in- 

 vestigations suggested by this and other considera- 

 tions. Professor Moissan, of Paris, has succeeded 

 in preparing diamonds similar in every respect to 

 those formed naturally. In some earlier experi- 

 ments, it was found that when charcoal (or carbon) 

 is dissolved in various fused metals at the tem- 

 perature of the electric furnace, it invariably 

 crystallizes out in the form of graphite, and under 

 increased pressure it forms black diamonds. In 

 the process which eventually succeeded, an excess 

 of charcoal and iron are melted together in the 

 highest temperature of a specially contrived electric 

 furnace, until the carbon is dissolved in the molten 

 iron. The carbon and iron solution is then cooled 

 by pouring it into just melted lead, in which, being 

 lighter than the lead, it rises to the surface in 

 globules. On removing the surrounding iron from 

 these globules, the carbon contained therein 

 appears in the form of true diamonds, possessing 

 the hardness and density, the limpidity and high 

 refractive power of the native diamonds. The 

 stones so produced, though small, are in fact 

 equal in every respect to those occurring 

 naturally. 



Many investigations have been made in the 

 endeavour to produce by chemical means, rubies, 

 sapphires, and other stones, but though true gems 

 are produced, identical in hardness and composition 

 with the natural stones, the brilliancy and beauty 

 of the latter are not usually attained. Alumina has 

 been fused with traces of chromium, and, by a long 

 process of cooling, has crystallized in the form of 

 rubies or sapphires, which were, however, of an 

 inferior kind. Opals have also been obtained from 

 solutions of silicates and the use of electric 

 currents. Complete success has, moreover, been 

 attained in the artificial formation of the spinels. 

 By the aid of boracic acid as a solvent for their 

 constituents, they have been obtained on re- 

 moving the boracic acid at a high temperature, 

 in crystals of great beauty, which could not be 

 distinguished by any test from those occurring 

 naturally. 



Those artificial formations which have been 

 most successful have only been accomplished by 

 most difficult processes, involving very great 



expense. They are interesting chiefly as a remark- 

 able instance of rnan's power to compete with 

 nature in a field where she has been most 

 mysterious and unapproachable. From the practi- 

 cal standpoint, the chemical methods have not 

 much commercial value, for their expense and 

 difficulty render the artificial stones more costly 

 even than natural gems of the same size and 

 quality. Possibly, however, in the near future, 

 the chemist will be able to produce large and 

 beautiful stones on demand, and the enormous 

 prices now paid for natural gems of the kind will 

 become a feature of the past. It seems probable, 

 moreover, that, regarded as artificial products, 

 precious stones will be dethroned from their unique 

 position. Works of art, it is true, are greatly 

 valued, and the skill exercised in their production 

 adds greatly to the admiration they excite, but the 

 excessive appreciation of famous gems is derived 

 from considerations of a different kind. They stand 

 alone and unrivalled in nature, and command 

 respect, not only as most beautiful products of 

 nature's marvellous skill, but also as rare specimens 

 only granted capriciously to luckier members of 

 mankind. We may, however, look to the time 

 when large and beautiful gems may be produced 

 at will, and all the secrets of their formation will 

 become familiar ; and while we rejoice at the 

 extension of human power and knowledge, we 

 must with some sadness admit that much of the 

 poetry and romance associated with these treasures 

 will be lost. 



Hawthorne Villa, Ferry Road, Edinburgh; 

 September iSth, i8g6. 



The Davy-Faraday Research Laboratory. — It 

 is nearly a year and a-half since Dr. Ludwig Mond, 

 F.R.S., founded the Davy-Faraday Research 

 Laboratory and presented it to the Royal Institu- 

 tion (see SciENCE-Gossip, N.S., vol. i, p. 121). 

 The interval has been applied in making the 

 structural alterations and fitting the building with 

 all the necessary appliances. The Laboratory was 

 duly opened on the 22nd ult., by the Prince of 

 Wales, and after the inaugural ceremony Professor 

 Dewar showed experiments illustrative of the use 

 of liquid air in scientific research. The Laboratory 

 is for research in pure chemistry and physics. Only 

 those will be admitted who have already done 

 original scientific work, or who in the opinion of 

 the Laboratory Committee are qualified to under- 

 take it. Nobody is to be excluded on the grounds of 

 nationality or sex, and admission to the Laboratory 

 and the supply of gas, water and electricity, as far 

 as available, will be free of charge. Lord Rayleigh 

 and Professor Dewar have been appointed Directors 

 of the Laboratory, and Dr. Scott will be the 

 Superintendent. 



