373 PHYSIOGRAPHY. CLASS n. 



the individuals being of various sizes and strongly 

 connected. 



OBSERVATIONS. 



1. If pure, it is entirely composed of oxide of titanium, 

 T, containing, according to Mr H. ROSE, 66-05 of metal, 

 and 33-95 of oxygen. By itself it is infusible before the 

 blowpipe, but gives with borax in the reducing flame a yel- 

 low glass, which assumes an amethyst colour when farther 

 reduced. 



2. It occurs generally in imbedded crystals, either in 

 the masses of rhombohedral Quartz engaged in gneiss, 

 mica-slate, and other rocks, or in beds, consisting of rhom- 

 bohedral Quartz, dodecahedral Garnet, several species of 

 Augite-spar, &c. It is sometimes found massive in metal- 

 liferous beds. It is likewise a production of ancient veins, 

 and often inclosed in transparent crystals of rhombohedral 

 Quartz. It occurs in the shape of pebbles in some gold 

 stream works. 



3. Imbedded crystals in Quartz have been found at Ro- 

 senau in Hungary, Teinach on the Bacher in Stiria, and 

 various localities along the chain of the Alps, also at Cri- 

 anlarich in Perthshire, and other places in Scotland, &c. 

 Very perfect crystals occur in the Saualpe, and in the 

 neighbourhood of Windisch-Kappel in Carinthia ; massive 

 varieties in the metalliferous beds of Arendal in Norway. 

 Switzerland and Savoy include many localities where it 

 occurs in veins, sometimes in reticulated shapes. Peb- 

 bles have been found at Ohlapian in Transylvania, and 

 called Nigrine on account of their dark colour. At St 

 Yrieix in France and in the province of Guadalaxara in 

 Spain, the well known twin-crystals occur, often of very 

 considerable dimensions. St Gothard is the locality of 

 some finely crystallized varieties, associated with rhombo- 

 hedral Iron-ore. The present species occurs in greater or 

 smaller quantities in many countries, as in Germany, Bo- 

 hemia, Salzburg, Piedmont, Siberia, America, &c. Beau- 



