34 



MINERALS AND GEOLOGY 



The colours, &c., communicated to these glasses by the more com- 

 monly occurring constituent bodies, are shown in the annexed tabular 



view. 



Colour of Bead after exposure 

 to an Oxidating Flame. 



BORAX. 



Colour of Bead after exposure to 

 a Reducing Flame. 



,, , . , T ( Colorless, if quickly cooled. 



Violet or Amethystine ......... Manganese.... j violet-redif quickly cooled. 



Violet-brown (whilst hot) . . . . ) Nickel .......... Q and 



Clear-brown (when) cold ..... \ 



Blue (very intense) ............ Cobalt , .......... Blue (very deep). 



More or less colorless or in- 

 Green (whilst hot ........... former distinctly colored whilst 



Blue or greenish-blue (cold) . . " hot ; brownish-red and 



opaque on cooling. 

 Green or blueish -green ......... Cobalt -r Iron. . . .Green or blueish-green. 



\ Copper + Nickel ) Brownish-red, opaque on 

 Green (dark) .............. j C( ^ er + Ir(m { cooKng 



Yellowish or reddish (hot) . . | Chromium _ _ Emerald-green. 



Yellowish-green (when cold ..} 



Yellow (whilst hot) .......... j v .^in, I Brownish (whilst hot) 



Greenish-yellow (cold) ....... J v ' 1 Emerald-green (when cold). 



Yellowish or reddish .......... Iron ............ Bottle-green. 



g ! \ \ \ '. \ '. \ U 

 Yellow (whilst hot) ........ ) , Colorless or yellowish. 



S le ye i 10 ^T fl (C ' ^ ........ CenUm ........ Opaque-white, if saturated. 



Hnamelled by naming ....... ) 



, Yellow or yellowish-brown. 



Yellow (not) .............. Enamelled light-blue by 



Colorless (cold) . , .......... Titanium ....... flami ^ 



Enamelled by naming ........ ) y unde * phosphoY .^ t be _ 



Yellow or yellowish-brown. 

 Yellow (hot) ............. Enamelled by naming. 



Colorless cold) . . . .......... Tnngstenum .... y> under ^ ho her g salt 



Enamelled by naming ....... below 



v ,, ,, ,. Brown or grey, semi-opaque, 



CoVrLs or'ydlowish (ooli): : Molybdenum . . "j ^^Z^ 

 Greyish and opaque by flaming ) v unde / phosp hor-salt be- 



'Grey and opaque on cool- 



y , ing but after continued 



Yellow or yellowish-red (hot) j> ea ' ivl ' " ' subjection to the flame, 



Yellowish or colorless, and Sfr ...... { the glass becomes clear : 



often opaline, when cold . . A . . .......... the reduced metallic par- 



Antimon y ...... tides either collecting to- 



. gether or volatilizing. 



Yellowish (hot) ............. ) ( Color iess-the reduced 



Colorless cold ............. V Cadmium ...... \ . , , . 



Opaque-white when saturated. ) ( metal bemg 



