170 



to produce fusion, got tiny crystals of ruby when the melt was slowly 

 cooled. These crystals, like those of nature, were in the hexagonal sys- 

 tem, as shown by their external form. St. Clair de Ville and Caron pro- 

 duced rubies by fusion of alumina mixed with a little chromium oxide 

 and, on one occasion they got both rubies and sapphires in the same 

 crucible. These were Aery minute and had the usual crystal form of the 

 natural stones. Fremy. by means of a high temperature continued for 

 eight days, got rubies of the weight of one-third karat each. These also 

 were regular crystals. No success was had l)y any of these earlier work- 

 ers in obtaining rubies of commercial size 



About iss.') ihcrc licgan in come on tlie market, from Geneva, Switzer- 

 land, it is udw said, some rnl)ics wliich at first were sold as natural stones, 

 but wliicli. it dcvcioi^'d Inter, were made Ity fusing together small natural 

 rubies by means of the oxyliydrogen l»lowiiii)e. These rubies were gener- 

 ally luibl>ly, and tlie bubbles, unlike those in natural rubies, were spher- 

 ical, '{'here were also other signs by means of which the artificial char- 

 acter of these so-called "reconstructed" rubies might be detected. They 

 were generally too low in si)eci(ic gravity, jirobably owing to their bubbly 

 charactei-. and the color was a bit unnatural to the eye of an exi>ert. They 

 wi're. hiiwcver. crystallized alumina. I have not had the oiiixirlunity of 

 examining any of the drops thus produced while in the uncut condition, 

 so that 1 am unable to speak in regard to their crystal structure. The 

 cut stones ar<' tVcbly donblf id r.icl ing and sliow dichroism like the natural 

 rubies. 



It was not long befru'c the use of small natural rubies was discon- 

 tiiuied nnd jiurr aiuuiina uiixi-d with a littl'' clironiiuni oxide was substi- 

 tuted. It was in 1!»04 that Verneuil published his niellmd of pi'oduciug 

 true synthetic rubies by heating the above mixture in the llame of the 

 oxyliydrogen lilowiiiiie. The method employed by liiiii in inti'oducing the 

 jHiwdered material was exceedingl.v ingenious. A receptacle with a sieve 

 bottom was constantly tai»iHMl by a mechrinical laiijier and the dust fell 

 into the stream of oxygen and passed with it through tlie llame, which was 

 directed vertically downward uixin a supixtrt below. Uyyon this support 

 the boule grew, first the slender stem. fhen. with i>roper manipulation of 

 the flame the wider and wider dome, until, in souk; cases, the boule 

 weighed over one himdred karats. The (i-ystal character of these boules 

 and of the blue and jiink and white and yellow ones which lat<'r came to 

 be made, forms the iii'incipal subject of this jiajier. 



