[ 44 ] 



■^J. Molybdenum. Iron-grey, brittle, compofed of fcaly parti- 

 cles; melting with great difficulty, gradu- 

 ally becoming a white volatile oxyde whe^ 

 heated, which with the addition of borax 

 is reducible to a violet glafs: fpecific gra- 

 vity 7,500. 



98. Uranium. Park- grey inclining internally to brown, 



fcft, opake, melting with extreme difficul- 

 ty ; convertible into a yellow powder by 

 means of the nitric acid: fpecific gravity 

 6,440. 



99. Titanium. Orange red, very hard, in minute aggluti- 



nated grains; |iot fufible by any known 

 heat, forming a blue or purple Qxyde when 

 heated: fpecific gravity . 



100. Chromium. White with a ihade of yellow, very brittle; 



melting with difficulty, diflblving (lowly 

 in acids; gradually becoming a green ox- 

 yde when heated in a clofe vefTel : fpecific 

 gravity . 



101. Columbium. Dark brown-grey, hardifh, very bittle, of 



an imperfc6lly lamellar texture ; yielding 

 wheti pounded a dark chocolate-brown 

 powder which is not attracted by the mag- 

 net; yielding a black powdery oxyde when 

 expofed to a very violent heat : fpecific 

 gravity 5,918 



102. Tantalium. Blacki(h-grey, foftifh, of a granular frac- 



ture, not foluble in any acid, nor altering 

 its colour when healed to rednefs ; yield- 

 ing a white powdery oxyde: fpecific gra- 

 vity 5,130. 



