INGENUITY AND LUXURY 



to the square inch. In the depths of the earth, such 

 a weight may be applied by the weight of geological 

 strata; but how may it be obtained in the laboratory? 



A most ingenious answer to this question was found 

 by the late Prof. Moissan of Paris. It is based on the 

 well-known fact that the metal iron has the peculiar 

 property, which it shares with a few other substances, 

 including water, of expanding instead of contracting 

 as it passes from the liquid to the solid state ; combined 

 with the further fact that liquid iron absorbs or dissolves 

 carbon, much as water does sugar, in increased quantity 

 with increased temperature. Moissan filled an iron 

 receptacle with pure iron and pure carbon obtained 

 by calcining sugar; closed it tightly and heated it rapidly 

 to the highest attainable temperature in an electric 

 furnace bringing it to a degree of heat at which the 

 lime furnace begins to melt, and the iron to volatilize 

 in clouds. The dazzling fiery receptacle, before it 

 has had time to melt, is lifted out and plunged instantly 

 into cold water until its outer surface is cooled and 

 hardened, thus forming a shell of iron that holds the 

 interior contents in an inflexible grip. As this molten 

 interior matter cools, the carbon separates from the 

 iron solvent in liquid drops ; and under the almost un- 

 imaginable stress of expansion of the solidifying iron, 

 these liquid drops become solid crystals of diamond. 



By a long slow process the iron ingot and the various 

 impurities are dissolved and fused away, until nothing 

 remains but the pure diamond crystals; and these 

 are but fragments of the crystals originally obtained, 

 which, having been formed in a condition of great inter- 



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