The St. Johns herald., 1897-03-20
MANUFACTURES DIAMONDS
p-of Moisson Uses Carbon aud Iron
 aud Crucible Furnace.

puof. Moisson Uses Carbon and Iron
 aud Crucible Furnace.
 Referring to the recent lecture lr New York of Prof. Henry MOisson, the French scientist, who makes diamonds the Evening World says;
 Prof. Moisson told how he had dls covered the composition of diamonds by reducing specimens of diamonds to ashes.
 The scientist found out by the process that in all these diamonds, save one very pure green gem from Brazil. there was iron, while the Cape diamonds came from earth that contained granite and graphite.
 Granite is the effect of great pressure. As cast iron increases in volume in nassing from the liquid to the solid state. he was led to believe that if an element of carbon were inclosed in 8 globule of cast iron that was cooling 1t would be subjected to the requisite pressure. He had experimented to as- certain the different stages through which carbon passes and had obtained pure carbon-graphite-by very high temperature.
 High temperature alone, however, would not yield the crystallized form of carbon known to commerce as 'dia- mOnd." Heat at sufficient pressure would, he believed, and he at last sue ceeded in proving 1t.
 In order to obtain heat sufficiently great and at the same time measurable, he devised a simple electric furnace, and there it was before his audience.
 It consisted of two clay bricks, one eighteen inches square on the surface and a foot thick, with another above t half as thick In the lower brick was a hollow large enough to contain the crucible, while two carbon electrodes connected with a battery entered the cavity, which was sprinkled with mag nesia to prevent the formation of cal cum carbide.
 Tn the crucible were placed sOft-irOn filings and charcoal. The furnace was covered up and the current turned on. In three minutes the indicator showed that things inside the little furnace were 2,500 degrees hot. The clay was boiling and flaming before their eyes. Prof. MoissOn carelesSly laid his hand on the top brick and kept 1t there-just to show that the heat didn't come through.
 At the end of ten minutes the little wizard turned off the current, lifted the cover the under side a white mass of flame, and dropped it in some water. He took out the crucible with tongs and dropped it into cold water
 When the crucible was cold he broke it and took out an ingot as big as q common bullet. He explained the proc eSs which he must go through to eln- mate the iron, in which was imbedded the cryStalliZed carbOn-the diamond
 Then the slender Frenchman spoiled 1t all by telling his audience that he had never been able to make a diamond larger than one millimetre In diameter l and of no commercial value, but he ! hoped later on to produce a regular | Searchlight." Then the sign "Dia. | monds made while you wait will be- come familiar.
 He told a lot of interesting things about diamonds. He said the little black specks found in diamonds. called ''crapaudS' Ill France, "pogs" in New York. which detract from the value of the stones, were the first proof to him that he had got on natures track.
 He said that when cooling the crucl- | ble in molten lead @ the crystal takes the shape of a rectangular figure, but when mercury is used ill cooling the the diamonds are octahedron. |
 These latter, like similar diamonds | found at the Cape fields, split when ex posed to the air-an additional proof to MolssOn that diamonds are produced 1 by pressure. These pressures are prin | clpally expansion power.