jgg EXTEttlMENTS ON MOL^'BDENA. 



(ifiiAe bedded a mass of violet brown oxide weighing one ounce. This mass 



in charcoal; j pjj^^ed in a criicible, surrounded it with powdered charcoal, 



and exposed it for an hour to the most violent forge fire. 



and reduced fhe result was a metallic mass, the different parts of which 

 by a violent i r t ^ , ■ , ^ 



iforgefire. "were more or less irothy, and more or less tenacious, but the 



tenacity was in no place such, but it might be beaten to pow-' 

 der. The exterior part was of an ash gray ; in the interior, 

 and even at the surface where cavities and depressions were 

 formed, it had a truly metallic lustre, and was of a silver 

 blue colour. The parts that had this lustre being pressed 

 upon and beaten in a porcelain mortar were extended a lit- 

 tle under the pestle, and this increased their brilliancy; but 

 bn continuing it they were reduced to a gray powder. Their 

 "hardness before trituration was greater than that of silver of 

 nine pennyweights (0"75), since they scratched it. 

 Attempt to ob'- In order to obtain this matter in small melted parts, I 

 bules""^ ^ °* pounded six drachms, which I pressed as strongly as possible 

 into a crucible lined with charcoal, and exposed to the most 

 violent forge fire for an hour and half. After cooling I found, 

 that the mass was agglutinated,anij reduced in bulk one fourth, 

 I could not gel it out without breaking the crucible. Thosi^ 

 parts which had been in contact with the button and sides 

 had considerable tenacity, but it was not the same with the 

 Agglutinated, surface. However, it could not be said to have been actu- 

 ^'l* f°' d^^"' ally fused in any place, its parts being merely agglutinated by 

 a commencen^ent of fusion. Every where it exhibited a large 

 quantity of scales, which were of a silvery white and a metal- 

 lic lustre. Bruised .on glass or porcelain, they acquired a 

 medium lustre between that of tin and that of silver; but 

 A fpw small this disappeared in twelve or fifteen minutes. At the bottom 

 bouo"m^\har^ ^^ '^® crucible appeared a few grains of molybdena, of the 

 had beep size of a pin's head, which had evidently been fluid. They 



were all over of a metallic lustre, and silvery white, like the 

 scales already mentioned. The lower part of the mass of 

 metallic molybdena, when beaten with a porcelain pestle, as- 

 sumed the same lustre*. 



Notwith- 



• Ruprecht appears to have observed something similar. Hesays, that 

 in endeavouring to reduce molybdena he obtained some small metallic 



grains 



fused. 



