82 



THOiMAS STEEKY HUNT ON A NATUEAL SYSTEM IN 



Pyricaustates, may be placed successively all the other orders : Oxydate, Silicate, Titanate, 

 Niobate, Taiitalate, Tuiigstate, Molybdate, Chromate, Vanadate, Autimouate, Arsenate, 

 Phosphate, Nitrate, Sulphate, Borate, Carbonate and Oxalate ; — an arrangement of these 

 orders of oxydized compounds in which general physical characters have been considered. 

 The Metallates, standing above, on one side, are connected with the vertical column by the 

 sulphuretted carbhydrates, by sulphuretted oxyds like kermesite and voltzite, and by 

 sulphosilicates like helvite and daualite. The Haloidates, on the other side, are connected 

 with the same vertical column by the oxychlorids, by chlorosilicates and fluorosilicates 

 like sodalite, pyrosmalite, tourmaline, chondrodite and topaz, and by the haloid elements 

 in certain arsenates, phosphates, borates and carbonates. The affiliations between the 

 orders in the vertical column are seen in titanosilicates like titanite and astrophyllite, in 

 niobosilicates like wohlerite, in sulphatosilicates like hauyne, in borosilicates like datolite 

 and tourmaline, and in carbosilicates like cancrinite. Of these orders, Metallates, Pyri- 

 caustates and Haloidates will each constitute a Class,— all the remaining orders being 

 included in another Class.' 



These four classes with their orders and suborders may be tabulated as follows : — 



Classes. 



II. 



III. 



Oedees axd Subobdek.?. 



1. Metallates : a. Metallometallates ; b. Spatlioniotallates. 



2. Oxydâtes. — 3. Silicates: a. Protosilicates; b. Protopersilicates ; e. Persilicates. — 



4. TiTASATBS. — .5. NiOBATES. — 6. TaNTALATES. — 7. TUNGSTATBS. — 8. MoLYB- 

 DATES. — 9. ClIEOMATES.— 10. VANADATES. — 11. AnTIMONATES- — 12. ARSENATE)?. 



— 13. Phospuates. — 14. Niteates. — 15. Sulpuates. — 16. Borates. — 17. Carbo- 

 nates. — 18. Oxalates. 



19. Haloidates : a. Fluorids ; 6. Clilorids ; c. Bromids ; (I lodids. 



IV. 



20. Pyricaustates : a. Carbates; 6. Carbbydrate?. 



§ 112. The conceptions of high molecular weights in mineral chemistry, and of the 

 existence of compounds like polycarbonates and polysilicates made up of a great many 

 chemical units, and including a large number of basic atoms, taught by the writer in 1853 



' Weisbach, the successor of Breitbaupt at Freiberg, published in 1875, in his Synopsis Mineralogica, a modifi- 

 cation of the system of Molis. Class I of Weisbach, Hydrolytb or Salts, includes compounds soluble in water; 

 while Class II, Lithe or Stones, is divided into three orders : 1. Kuplioxyde ; 2. PiirltHe (silicate), including four 

 families: a. Sklerite; h. Zeolite; c. Phyllite ; f^. Amorpbite; and 3. ApiirilUe (non-silicate). Cla.ss III, Mctaixitis 

 or Ores, is divided into four orders : I. Haloww.lallite ; 2. Metalloxyde ; 3. Mctalle ; 4. TMometalle, the last including 

 three families : a. Pyrite ; b. Galenite (Glances) ; e. Cinnabarite (Blendes). Class IV, Kauste or Combustibles, 

 includes five orders : 1. AmHallr (Sulphur); % ArMradte {Cosûs) ; 3. A^haltUr (Pitches); ^. Rhetinite (Resins); 5. 

 rfirajlirii' (Waxes). The silicates of heavy niotals are placed in Class III, but with these exceptions the Sklerite 

 include the siiathoi<ls and adamantoids, tlio Phyllite tlic phylloids, and tlio Amorpbite tlie colloids of our throo 



