MINERALOGY 123 



Spectral analysis of zinc blende from the Pyrenees led 

 BOISBAUDRAN to the discovery of gallium. Radium was 

 discovered by the CURIES as a result of careful investi- 

 gation of pitchblende and other uranium-bearing miner- 

 als. FRIEDEL and GRAND JEAN have recently studied the 

 nature of the water in zeolites, and have shown that 

 it can be expelled and reabsorbed or replaced by other 

 liquids or gases without destroying or changing the 

 nature of the crystal structure. 



The methods of synthetic mineralogy were developed 

 in France. FOUQUE and MICHEL-LEVY reproduced all 

 the minerals of volcanic rocks, except quartz and ortho- 

 clase, by means of crystallization from dry fusion. By 

 the same process, GAUDIN and VERNEUIL produced ruby 

 and sapphire, the manufacture of which has now become 

 an important industry. Fusion in the presence of min- 

 eralizers is a method which has yielded important results 

 in the hands of several experimenters, notably DEVILLE, 

 HAUTEFEUILLE, BOURGEOIS, GORGEU, FREMY, and 

 EBELMEN. Finally, several minerals have been produced 

 in the presence of water (or water-vapor) heated in a 

 sealed tube, by DAUBREE, SARASIN, and FRIEDEL. 



The minerals of metalliferous veins and ore deposits 

 are of much practical importance; BEAUMONT was the 

 first to present a complete and rational theory to explain 

 the origin of such deposits; many of the classic experi- 

 ments of DAUBREE were devised to shed light on the 

 same problem. DE LAUNAY has continued this work 

 and prepared scientific descriptions of the ores of the 

 world. 



