Synthetic Man Made Diamonds Hershey: Book of Diamonds Page 134



	THE BOOK OF DIAMONDS

	Sir William Crookes attributes the possibility of making artificial diamonds to the facilities afforded by the enormously high temperatures which have been obtainable only in recent years by the use of electricity. While electricity has, no doubt, played an important part in the scientific researches during the last decades of the nineteenth century, Mr. Hannay's experiments would indicate that it is not absolutely essential to have extremely high temperatures or pressures in order to produce artificial diamonds. Still Sir William Crookes shows that by means of these high temperatures substances such as carbon obey the common laws which govern other substances, and can be made volatile and fusible under certain conditions. He has demonstrated that the temperature necessary to volatilize pure carbon is about 3,600° C, and that it passes into the gaseous state without liquefying. He infers that, if, however, sufficient pressure were applied with the high temperature, liquid carbon would be produced which upon cooling would crystallize in diamonds. In making this product the absence of oxygen is absolutely necessary since carbon at high temperatures is chemically most energetic, and if it can possibly get at oxygen from the atmosphere or from any compound containing oxygen it will combine with it and fly off in the form of carbon dioxide. Heat and pressure, therefore, are of no value unless the carbon can be kept inert. Sir William Crookes went through the process of producing diamonds before the eyes of his audience, but was able to show them the result of his experiment only by pro- 126