TIME OF DISCOVERY OF THE METALS. 



131 



Platinum, 



1020 1868 



1100 2012 



1200 2192 



1800 3272 



Highest heat of forge. 



V Agglomerate, but do not melt in forge. 



f Fusible in the oxyhydrogen blowpipe 

 I flame. 



Specific gravities of metals at 15.5 C, 



Time of discovery of the metals. 



Gold, 



Silver, 



Mercury, 



Copper, 



Zinc, 



Tin, 



Iron, 



Lead, 



Antimony, 



Bismuth, 



Arsenic, 



Cobalt, 



Platinum, 



Nickel, 



Manganese, 



Molybdenum, 



Chromium, 



These metals were known to the ancients, because 

 either they are found in a metallic state, or can be 

 obtained by comparatively simple processes from 

 the oxides. 



> Latter part of the fifteenth century. 



1694, by Schroder. 

 1733, by Brandt. 

 1741, by Wood. 

 1751, by Cronstedt. 

 1774, by Galm 

 1782, by Hjelrn. 

 1797, by Vauquelin. 



