184 HYDRATE OF ALUMINA. 



Camp. Hydrate of alumina, or Al H^ 



= alumina 65'5G, Avater 34-44= 100. 



Analysis, from the Ural, bv Htrmann : 



Alumina . . / . 64-03 



Phosphoric acid . . . 143 



Water 34-54 



100-00 



BB whitens, becomes opaque, emits a 

 brilliant light, but does not fuse. 



In powder dissolves, but with difficulty, 

 in muriatic acid. 



Localities. The Schischimskian moun- 

 tains, near Slatoust, in the Ural, where it 

 was first discovered by Lissensko. Gumush^ 

 dagh in Asia Minor, associated with Corun- 

 dum. Unionville, Pennsylvania, U. S. Bra- 

 zil, resembling Wavellite. 



Name. From S^mo^ water, and a.^yiXX6s, 

 clay. 



HA'drargyllite bears some resemblance 

 in form to phosphate of lime; but is easily 

 distinguished from it bv inferior hardness. 



Brit. Mus., Case 19. " 



Hydrate of Alumina. See Diaspore. 



Hydrate of Magnesia, Allan, Phillips. 

 See Brucite. 



Hydrated Deutoxide of Manganese, 

 Turner. See Manganite. 



Hydrated Iolite, or Bonsdorffite. 

 See Hydrous Iolite. 



Hydro- ALUMINOUS Lead. See Plumbo- 

 Resinite. 



Hydro-apatite. Occurs in semi-trans- 

 parent mammillary concretions, somewhat 

 resembling Chalcedony. H. 5'5. S.G. 3-1. 



Comp. Ca^P + CaF- 

 Analysis : 



Phosphoric acid . 



Lime . 



Calcium 



Fluorine 



Phosphate of iron 



Water . 



H. 



40-00 

 47-3 L 

 3-60 

 3-33 

 0-43 

 5-30 



100-00 



Heated in a tube, decrepitates and disen- 

 gages ammoniacal water. 



Locality. The Pj'renees, in fissures of a 

 ferruginous-brown argillaceous rock. 



Name. From (^'^m^, water, and apatite. 



Hydroborocalcite, or Hayesine. The 

 name (derived from y'^w?, water, boron, 

 and calcium, lime'), has reference to its che- 

 mical composition. See Hayesine. 



Hydroboracite, Hess, Dufrenoy, Brooke 

 §• Miller. Resembles in appearance a worm- 

 eaten Avood, and is riddled with small holes. 



HYDROCARBONATE OF MAGNESIA, 

 which are filled with a mixture of clay and 

 salt. 



Colour white, with red spots caused by 

 the presence of iron. Structure radiating 

 foliated, and resembling fibrous and foliated 

 Gypsum. Transparent in thin plates. II. 2. 

 S.G. 1-9 to 2. 



Comp. Hydrated borate of magnesia and 



lime, orCa^ B^ + Mg B* + 18H=lime 14-3, 

 magnesia 10-3, boracic acid 47-7, water 27-7 

 -100-0 

 Analysis, by Hess : 



Lime 13-30 



Magnesia .... 10-45 

 Boracic acid . . . 49-92 



Water . . . . . 26-33 



100-00 



BB fuses readily, with considerable loss 

 of water, to a clear glass, imparting at the 

 same time a greenish colour to the flame. 



Yields borate of magnesia to boiling water, 

 imparting to it an alkaline reaction. 



Very soluble in warm muriatic acid. 



Locality, The Caucasus. 



Name. The name (from vSa^, water, and 

 Boracite), has reference to its chemical com- 

 position. 



"Hydroboracite may be distinguished from 

 Gypsum, to which it bears a strong resem- 

 blance, by its fusibility. 



Hydrobucholzite. Probably an altered 

 or hydrous Kvanite, from Sardinia. 



Hydrocalcite. Occurs in small rhom- 

 bohedral crystals, and forming an incrusta- 

 tion on wood under water. 



Colour whitish, bluish, greyish. Translu- 

 cent. Easily broken. Fracture splintery. 

 S.G. 2-58. 



Comp. CaC + 5H= carbonate of lime 52-4, 

 water 47-6 = 100. 



Analysis, from the Giants' Causeway, by 

 Da Costa : 



Lime ..... 47-0 

 Carbonic acid . . . 36-0 



Silica 3-0 



Alumina .... 2-0 

 Water 12-0 



100-0 



The water passes off*, and the mineral be- 

 comes anhydrous on exposure to the air. 



Locality. The Giant's Causeway, on 

 basalt. 



Name. From, ij^i^?, water, and calci te, CaZc 

 Spar. 



Hydrocarbonate of Magnesia, Thom- 

 son, See Hydromagnesite. 



