146 THE ATOMIC WEIGHTS. 



Two reduction experiments by Persoz * give the following 

 results : 



1-7999 g"Ti- WO3 gave 1.4274 grm. W. 79.304 per cent. 



2.249 " 1-784 " 79-324 " 



Mean, 79.314, ±z .007 



Finally, we have the work done by Roscoe.f This chem- 

 ist used a porcelain boat and tube, and made six weighings, 

 after successive reductions and oxidations, with the same 

 sample of 7.884 grammes of trioxide. These weighings 

 give me the following five percentages, which, for the sake 

 of uniformity with foregoing series, I have classified under 

 the usual, separate headings : 



RechulioJi Series. 

 79.196 

 79-285 

 79.308 



Mean, 79.263, zn .023 



Oxidation Series. 



79.230 

 79.299 



Mean, 79.2645, rt .0233 



There are still other experiments by Riche,| which I have 

 not been able to get in detail. They cannot be of any value, 

 however, for they give to tungsten an atomic weight of about 

 ten units too low. We may therefore neglect this series, 

 and go on to combine the others : 



Berzelius 79 



Schneider, Reduction 79 



" Oxidation 79 



Marchand, Reduction 79 



" Oxidation 79 



V. Borch, Reduction 79 



" Oxidation 79 



* Zeit. Anal. Chem., 3, 260. 1864. 



f Ann. Chem. Pharm., 162, 368. 1872. 



J Journ. fiir Prakt. Ghem., 69, 10. 1857. 



