208 THE ATOMIC WEIGHTS. 



From per cent. TiO.^ Ti = 50.493, ± .410 



" AgCl : TlC\^ " = 48.232, zb .127 



" AgCl : TiO.^ " = 49-523, ± .206 



General mean " = 48.710, zb .105 



These results will be discussed further along in connection 

 with others. 



Sliortl}^ after the appearance of Rose's paper, Mosander * 

 published some figures giving the percentages of oxygen in 

 titanium dioxide, from which a value for the atomic weight 

 of titanium was deduced. Although no details are furnished 

 as to experimental methods, and no actual weighings are 

 given, I cite his percentages for whatever they may be worth : 



40.814 

 40.825 

 40.610 

 40.180 

 40. 107 

 40.050 

 40.780 

 40.660 

 39-830 



Mean, 40.428 



These figures give values for Ti ranging from 46.277 to 

 48.231 ; or, in mean, Ti = 47.045. They are not, however, 

 sufficiently explicit to deserve any further consideration. 

 It will be noticed that the highest value nearly coincides 

 with Rose's lowest. 



In 1847 Isidor Pierre made public a series of important 

 determinations.! Titanium chloride, free from silicon and 

 from iron, was prepared by the action of chlorine upon a 

 mixture of carbon with pure, artificial, titanic acid. This 

 chloride was weighed in sealed tubes, these were broken 

 under water, and the resulting hydrochloric acid was 

 titrated with a standard solution of silver after the method 



* Berz. Jahresbericht, lo, io8. 1831. 

 t Ann. de Cliim. et Phys., (3,) 20, 257. 



