256 



THE ATOMIC WEIGHTS. 



Closely agreeing with these figures are those of Marchand,* published 

 in the following year : 



Reduction Series. 



79.307 

 79.302 



Mean, 79.3045 



Oxidation Series. 

 79.321 

 79.352 



Mean, 79-3365 

 Mean of all, 79.3205, =h .0073 



The figures obtained by v. Borch f agree in mean tolerably well with 

 the foregoing. They are as follows : 



Reduction Series. 



79.310 

 79.212 

 79.289 



79.313 

 79.225 

 79.290 

 79.302 



Mean, 79.349 

 Mean of all, 79.293, zt .0108 



Dumas % gives only a reduction series, based upon trioxide obtained 

 b}^ the ignition of a pure ammonium tungstate. The reduction was 

 effected in a porcelain boat, platinum being objectionable on account of 

 the tendency of tungsten to alio}' with it. Dumas publishes only 

 weighings, /rom which I have calculated the percentages : 



2.784 grm. WO3 gave 2.208 gini. W. 



2.994 " 2.373 



4.600 " 3.649 " 



.985 " .781 " 



.917 " .727 " 



.917 " .728 " 



I. 717 " 1.362 " 



2.988 " 2.370 " 



* Ann. Chem. Pharm., 77, 261. 1851. 



t Journ. fi'ir Prakt. Chem., 54, 254. 1851. 



J Ann. Chem. Pharm., 113, 23. 1S60. 



