The daily morning journal and courier., 1906-04-12

pecting and in sinking artesian wells It. seems not beyond the bounds of. pos sibility that M. Moissans artificial diamonds may be employed eventually for such purposes as these, though there seems to be little hope of pro- ducing large and clear stones by such methods.
 Recently MT. c. V. Burton of the Cambridge Scientific Instrument Com pany has succeeded in producing small diamonds by less heroic method. There are theoretical reasons for think ing that if the specialization of carbon could be conducted at a comparatively low temperature high pressure might not be essential to the production of diamond rather than graphite.
 Mr. Burton uses an alloy of the metal calcium and lead as a solvent | for carbon. Calcium is tbe metallic constituent of lime and has only very recently been obtainable. It is very oxidizable metal-very anxious, in fact, | to return to the lime from which it came. By blowing steam into the alloy the calcium is converted into lime, and as lead is not able by itself to dissolve l carbon the carbon has to separate out. There seems to be little doubt that it l appears in the form of diamond
 though here again the diamonds are microscopic. This process seems far ' more capable of development into a practical form, for it can be conducted
 without tine difficult condition of very high pressure.
 Attempts to prepare rubies have been far more successful. Indeed some years ago the market for these stones, especially in Paris, was very con
 siderably disturbed by large influx of
 stones of unknown origin, and there is
 little doubt that they were made by an artificial process, though exactly how andwhere has, we believe, never trans
 pired. Recently M Verneuil has
 worked out a process for producing l rubies, and his products rival the best
 natural stones, though under the
 microscope they can be distinguished
 by the presence of minute bubbles l Ruby Is chemically composed of alumina, or oxide of aluminium, to-
 gether with a minute proportion of chromium which gives the characteris-
 tic color. The problem to be faced in making artificial rubies is to melt i such mixture and allow 1t to solidify
 into crystal free from flaws and large i bubbles. To melt 1t in any ordinary
 way, as, for instance, by directing an
 oxyhyrogen blowpipe on to lump of the material, is quite useless, since an
 opaque mass full of cracks Is all that
 results.
 M. Werneuil has found, however, that I if the mass is gradually built up by the successive addition of powdered mater ial while it is kept melted by the blow
 pipe flame, large and transparent crystal can be obtained. He ingenious
 ly effects this by making the gases of
 the blowpipe convey this powder on to
 the mass while they keep it hot. The
 blowpipe is directed downward and the : current of powder is fed into it through concentric tube, which is continually
 tapped, so as to insure constant sup
 ply.
 In few hours fine ruby is obtained often quarter inch in diameter, and , only distinguishable from the natura stone under the microscope These rubies often split into two parts, but : after that has happened they do no show any tendency to break into small
 CT pieces and are perfectly able to en dure cutting. M. Verneull thinks it no improbable that the process ma! eventually be still further improved, ,sC l as to make the stones indistinguiselabl 3 from real nnes. even hY exnerts.