ATOMIC WEIGHTS 281 



If we directly compare the AgCl with the TiOj we shall find 100 parts 

 of the former proportional to the following quantities of the latter: 



14.243 

 14.081 

 14.153 

 14.373 

 14.324 



Mean, 14.235, ± .036 



Hence Ti = 49.617. 



Shortly after the appearance of Eose's paper, Mosander ^ published 

 some figures giving the percentage 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 weigh- 

 ings 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 46.38 to 48.34; or, in 

 mean, Ti = 47.15. They are not, however, sufficiently explicit to deserve 

 any farther consideration. 



In 1847 Isidor Pierre made public a series of important determina- 

 tions." Titanium chloride, free from silicon and from iron, was pre- 

 pared 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 tlie resulting hydrochloric acid was titrated 

 with a standard solution of silver after the method of Pelouze. I subjoin 

 Pierre's weighings, and add, in a third column, the ratio of TiCl^ to 100 

 parts of silver: 



1 Beiz. Jahresbericht, 10, 108. 1831. 

 - Ann. Chim. Phys. (3), 20, 257. 



