44 



Dr. T. E. Thorpe. 



[Nov. 22, 



some experimental support from the observations of Rose. The 

 direct evidence in favour of either value is, however, very slight, and 

 a critical examination of the observations affords no ground for 

 assuming that Rose's value is nearer the truth than that of Pierre. It 

 is probable that the value 48 has been adopted in one or two modern 

 text-books, mainly because it agrees best with the requirements of the 

 periodic law. 



I have attempted to deduce the atomic weight of titanium from 

 observations made with the tetrachloride, the tetrabromide, and the 

 dioxide. The present communication contains the results furnished 

 by the analysis of the chloride. The work with this body affords 

 three independent values for Ti based on the ratios — 



I TiCl 4 : 4Ag 



II TiCl 4 : 4AgCl 



III TiCl 4 : Ti0 2 



Series I. — TiCl 4 : 4Ag. 



Weighed quantities of the tetrachloride were decomposed by water 

 in closed vessels, and the chlorine precipitated by silver after the 

 method of Gay-Lussac as modified by Stas — 





Chloride taken. 



Silver 



employed. 



Ti (H = l) 



I 



2-43275 .. 



5 



52797 .. 



. 48 -06 



II 



5 -42332 . . 



.. 12 



•32260 . . 



. 48 -07 



III 



, . , 3 -59601 . . 



8 



•17461 . . 



. 47 -99 



IY 



3 -31222 . . 



.. ' 7 



•52721 .. 



. 48 -05 



Y 



4 -20093 . . 



9 



•54679 . . 



. 48 -05 



YI 



5 -68888 . . 



.. 12 



•92686 . . 



. 48 -06 



YII 



5 -65346 . . 



.. 12 



•85490 . . 



. . 47 -95 



YIII 



, . . . 4 -08247 . . 



9 



•28305 . . 



. . 47 -94 





34 -39004 



78 



•16399 



48 -021 



Series II.— TiCl 4 : 4AgCl. 



Weighed portions of the tetrachloride after decomposition with 

 water were treated with excess of silver nitrate, and the silver 

 chloride separated by reverse filtration and weighed — 



Chloride taken. Silver chloride. Ti (H = l). 



IX 3-31222 .... 10-00235 .... 47 '99 



X 4-20093 .... 12-68762 .... 47*98 



XI 5-68888 .... 17-17842 .... 48 '00 



XII 5-65346 .... 17-06703 .... 48*06 



XIII 4 -08247 .... 12 "32442 .... 48 '06 



22 -93796 



69 -25983 



48 -018 



