146 SMITH AND EXNER — ATOMIC WEIGHT OF TUNGSTEN. [April 7, 



ignition were those which any careful analyst would observe, so 

 that they need not be mentioned here. The final oxide was uni- 

 formly yellow in color throughout its entire mass. 



The weighings here, as in all previous experiments, were reduced 

 to vacuum standard. The value of oxygen was placed at i6. The 

 specific gravity of the oxide was, as before, 7.157, and that of the 

 metal — 19. 



In the appended table it is to be understood that each single 

 series was made from portions of the same sample of metal. The 

 results are : 



In series VII, a very large quantity of oxide was heated in 

 hydrogen from 9 A.M. until 5 P.M. The resulting metal was 

 placed over night in a desiccator, and on the following day a por- 



