THE ALUMNI JOURNAL 133 



HOW DIAMONDS ARE FABRICATED. 



The manufacture of diamonds has been successfully performed by 

 one of the many modern chemists who have essayed it. M. Henri 

 Moissan, the diamond maker in question, is ateut to see his life work 

 commemorated by the presentation of a medal, which his pupils have 

 decided to ofifer to him on the occasion of the twentieth anniversary of 

 his successful isolation of fluorine. 



The value of M. Moissan 's work has been further acknowledged 

 by the award to him of the Noebel Prize for chemistry. 



But the isolation of fluorine is only one of M. Moissan's claims 

 to distinction. The electric furnace, which nowadays plays so large a 

 part in industrial processes, owes more to him than to any other ex- 

 perimenter. 



Mr. Moissan's pattern of electric furnace consists in its simplest 

 form of two blocks of lime or limestone, forming the body of the fur- 

 nace, through which an arc was formed between carbon electrodes. 

 The peculiarity of M. Moissan's furnace was that it was able to pro- 

 duce far higher temperatures than had previously been attained. As 

 much as a hundred horse power was used to concentrate its energy 

 on a small charge, and in this way a temperature was reached only 

 limited by the boiling point of carbon, which lies between six and 

 seven thousand degrees Fahrenheit. 



At this tremendous temperature, which is probably net far off 

 that which exists in the sun's atmosphere, the most refractory metals 

 are converted into vapor, and chemical changes or combinations are 

 produced which are quite impossible at the comparatively low tempera- 

 ture of ordinary furnaces. 



The most interesting, though not the most industrially important, 

 of the researches which M. Moissan has carried out in his electric 

 furnace is the manufacture of artificial diamonds. We have long 

 known that the diamond is only a piece of crystallized carbon. If we 

 could melt carbon and allow it to cool slowly, there is no doubt that 

 it would solidify into the brilliant crystals which we call diamonds. 

 Unfortunately, carbon cannot be melted at all under ordinary condi- 

 tions. It is one of the few elements which pass directly from the solid 

 to the gaseous condition — like iodine. M. Moissan, like earlier in- 

 vestigators, had therefore, to abandon the idea of thus forming dia- 

 monds. 



