TUNGSTEN. 



Oxidation Series. 

 79-359 

 79-339 



145 



Mean, 79.349, d= .0067 



Dumas * gives only a reduction series, based upon trioxide 

 obtained by the ignition of a pure ammonium tungsten. 

 The reduction was effected in a porcelain boat, platinum 

 being objectionable on account of the tendency of tungstate 

 to alloy with it. Dumas publishes only weighings, from 

 which I have calculated the percentages : 



The data furnished by Bernoullif differ widely from those 

 just given. This chemist undoubtedly worked with impure 

 material, the trioxide having a greenish tinge. Hence the 

 results are too high. These are the percentages of W : 



Reduction Series. 

 79-556 

 79-526 

 79-553 

 79-558 

 79-549 

 78.736 



Mean, 79.413, 4; .091 



Oxidation Series. 

 79-558 

 79-656 

 79-555 

 79-554 



Mean, 79.581, i .017 



10 



* Ann. Chem. Pharm., 113, 23. i860, 

 f Poggend. Annal., in, 573. i860. 



