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───────────────┬───────────────┬───── │ │_Molecular _Materials._ │ _Formulae._ │Weight._ ───────────────┼───────────────┼───── Alumina │Al_{ 2}O_{ 3} │ 102 Antimony Oxide │Sb_{ 2}O_{ 3} │ 287 Arsenic │As_{ 2}O_{ 3} │ 197 Bismuth Oxide │Bi_{ 2}O_{ 3} │ 468 Boric Acid │H_{ 3}BO_{ 3} │ 62 Borax │Na_{ 2}B_{ 4}O_{ 7}10H_{ 2}O│ 382 Calcined Borax │Na_{ 2}B_{ 4}O_{ 7}│ 202 Calcined Potash│K_{ 2}CO_{ 3} │ 138 Carbon │C │ 12 Carbonate of │BaCO_{ 3} │ 197 Barium │ │ Carbonate of │MgCO_{ 3} │ 84 Magnesia │ │ China Clay │2SiO_{ 2}Al_{ 2}O_{ 3}2H_{ 2}O│ 258 Chrome Oxide │Cr_{ 2}O_{ 3} │ 153 Cobalt Oxide │Co_{ 2}O_{ 3} │ 105 Copper Oxide │Cu_{ 2}O │ 143 (Red) │ │ Copper Oxide │CuO │ 79 (Black) │ │ Cryolite │6NaFAl_{ 2}F_{ 6}│ 210 Dolomite │CaOMgO2CO_{ 2} │ 184 Fluorspar │CaF_{ 2} │ 78 Gold Chloride │AuCl_{ 3}2H_{ 2}O│ 339 Iron Oxide │Fe_{ 2}O_{ 3} │ 160 Lime │CaO │ 56 Lime Spar │CaCO_{ 3} │ 100 Manganese Oxide│MnO_{ 2} │ 87 Nickel Oxide │NiO_{ 2} │ 75 Nitrate of Soda│NaNO_{ 3} │ 85 Phosphate of │Ca_{ 3}(PO_{ 4})_{ 2}│ 310 Lime │ │ Potash │K_{ 2}CO_{ 3}(2H_{ 2}O)│ 174 Carbonate │ │ Potash Felspar │6SiO_{ 2}Al_{ 2}O_{ 3}K_{ 2}O│ 556 Red Lead │Pb_{ 3}O_{ 4} │ 683 Saltpetre │KNO_{ 3} │ 101 Sand │SiO_{ 2} │ 60 Soda Carbonate │Na_{ 2}CO_{ 3} │ 106 Sodium Fluoride│NaF_{ 3} │ 61 Sulphate of │Na_{ 2}SO_{ 4} │ 142 Soda │ │ Tin Oxide │SnO_{ 2} │ 150 Uranium Oxide │UO_{ 2} │ 272 Zinc Oxide │ZnO │ 81 ───────────────┴───────────────┴─────
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THE CHEMICAL AND PHYSICAL PROPERTIES OF GLASS
The main essential and peculiar property of glass is its transparency. When subjected to a gradually increasing temperature, glass becomes softened, and whilst hot it is plastic, ductile, and malleable, in which state it can be cut, welded, drawn, or pressed. A thread of glass can be drawn so thin and fine that it can be twisted and bent to a remarkable extent, showing that glass is flexible.
The above properties shown by glass while softened under heat permit it to be shaped and formed by a variety of methods, so that in the manufacture of the different kinds of glass we find goods pressed, blown, drawn, moulded, rolled and cast from the hot metal. Upon cooling, the form given to them is retained permanently.