ATOMIC WEIGHTS 



285 



In short, the work of Eose, Pierre and Demoly practically vanishes. 

 Furthermore, as will be seen later, the three ratios now give closely 

 agreeing values for the atomic weight of titanium. The cross ratio, 

 4AgCl:Ti02 is not directly given by either of Thorpe's series; but the 

 data furnished by Rose and Demoly combine into a general mean of 

 4AgCl : TiO. : : 100 : 13.980, ± .0303. 



Some two years later Thorpe published his work more in detail,' and 

 added a set of determinations, like those made upon the chloride, in 

 which titanium tetrabromide was studied. Three ratios were measured, 

 as was the case with the chloride. In the first, the bromide was decom- 

 posed by water and titrated with a silver solution. 



Mean, 85.235, it .0027 



Hence Ti = 48.127. 



In the four last experiments of the preceding series, the silver bromide 

 formed was weighed. The third column gives the TiBr^ proportional to 

 100 parts of AgBr. 



Mean, 48.962, ± .0049 



Hence Ti = 48.123. 



For the third ratio the bromide was decomposed by water; and after 



evaporation with ammonia the residual titanic oxide was ignited and 

 weighed : 



TiBi\. TiO.. Per cent. TiO... 



6.969730 1.518722 21.790 



8.836783 1.923609 21.768 



9.096309 1.979513 21.762 



Mean, 21.773, ± .0062 



Hence Ti = 48.070. 



1 Journ. Chem. Soc, 47, 108 and 129. ISSo. 



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