Moissan, however, was not the first to produce diamonds artificially. As soon as Lavoisier had experimentally shown that the chemical composition of the diamond and carbon are the same, efforts were made to convert charcoal into diamonds, and Despretz, as early as 1849, by means of the combined influence of a powerful burning glass, the oxyhydrogen blowpipe, and the carbon voltaic arc obtained a very high temperature. He claims by this temperature to have been able to change carbon into a few microscopic diamonds. It is quite possible, in the light of later investigations, that Despretz may have been mistaken in his belief that he had actually produced diamonds; but whether this be so or not, he was certainly one of the pioneers in this early transformation of charcoal. Theoretically, all that would be required in order to change the non-crystalline form of carbon into the diamond, would be to subject the carbon to a temperature sufficiently high to fuse it and then permit it slowly to crystallize. Could this be done, there should be no trouble in transforming any amount of coal into any equal amount of diamonds. But the transformation is by no means as simple as might be supposed. It is not that the temperature of the carbon cannot be raised to its point of fusion, but that as soon as a certain temperature has been reached, the carbon, instead of fusing or melting, is suddenly volatilized or turned into vapor. There is no doubt that this is done. Thousands of feet of carbon rods are volatilized every night in the arc lamps of our cities, but the trouble is that this carbon vapor so formed, when cooled, or condensed, is not converted into the exceedingly hard, clear, crystalline diamond, but into the soft, dull black graphite or plumbago. Now the process adopted by Moissan in order to cause volatilized carbon, or carbon vapor, to condense in the form of crystalline diamonds was practically as follows: he placed pieces of pure carbon inside a very strong steel tube, such, for example, as would be formed by boring a short cylindrical hole in a piece of strong thick steel, and placing a small quantity of carbon inside the tube so formed. Closing the open end of the tube by means of a tightly fitting screw plug, he volatilized the carbon inside the tube. The steel, tube, and plug formed an electric furnace, for, as soon as he passed an electric current through it, the temperature at once became high enough to volatilize the carbon. Under these circumstances the carbon vapor was subjected to great pressure owing to the limited space in which it was liberated. As soon as this mass of dense vapor had been formed, he seized the steel tube with a pair of furnace tongs, and plunged it below the surface of cold water in a bucket.