14 CATALOGUE OF PHILOSOPHICAL APPARATUS. 



C. MINERALS IN WHICH SILICA STANDS ALONE, on is 



ONLY COMBINED WITH WATER. 

 Drawers 22 to 28. Examples: Rock crystals, agates, opals. 



D. SILICA IN COMBINATION WITH BASES, 

 i. A with a single base isomorphous with lime (SiO, RO.) 

 Drawers 29, 30, 31. Examples; Serpentine, asbestos, talc. 



2. Silica with a single base isomorphous with alumina (SiO, R2 03.) 

 Drawers 32, 33. Examples: Cyanite, chiastolite. 



3. Silica with several bases isomorphous with lime (SiO with several RO.) 



I. Without water. 

 Drawer 32, 33, 34. Examples: Augite, olivine, hornblende. 



II. With water. 

 Drawer 35. Examples: Schiller spar, apophyllite, tremolite. 



4. Silica with several bases isomorphous with alumina (SiO, with several 



R2 03.) 

 Drawer 36. Examples: Beryl, bole, grenatite. 



5. Silica with several bases, some isomorphous with lime, or RO ; others with 

 Alumina, or R2 03. 



I. Without water. 

 Drawers, 37, 38, 39, 40, 41. Examples: Felspar, leucite, garnet. 



II. With water. 

 Drawers 41, 42, 43, 44, 45, 46. Examples: Zeolites. 



