ATOMIC WEIGHTS 283 



filtrate as silver chloride. Three analyses were performed, yielding the 

 following results. I give the actual weighings : 



1.470 grm. TiCl4 gave 4.241 grm. AgCl and .565 grm. TiO, 

 2.330 " 6.752 " .801 



2.880 " 8.330 " 1.088 



The ".801 " in the last column is certainly a misprint for .901. x\ssum- 

 ing this correction, the results may be given in three ratios, thus : 



These three ratios give three widely divergent values for the atomic 

 weight of titanium, ranging from about 36 to more than 56, the latter 

 figure being derived from the ratio between AgCl and TiCl4. This value, 

 56, is assumed by Demoly to be the best, the others being practically 

 ignored. 



Upon comparing Demoly's figures with those obtained by Eose, certain 

 points of similarity are plainly to be noted. Both sets of results were 

 reached by essentially the same method, and in both the discordance 

 between the percentages of titanic acid and of silver chloride is glaring. 

 This discordance can rationally be accounted for by assuming that the 

 titanic chloride was in neither case absolutely what it. purported to be; 

 that, in brief, it must have contained impurities, such for example as 

 hydrochloric acid, as shown in the experiments of Pierre, or possibly 

 traces of oxyehlorides. Considerations of this kind also throw doubt 

 upon the results attained by Pierre, for he neglected the direct estimation 

 of the titanic acid altogether, thus leaving us without means for correctly 

 Judging as to the character of his material. 



In 1883 ^ Thorpe published a series of experiments upon titanium 

 tetrachloride, determining three distinct ratios and getting sharply con- 

 cordant results. The first ratio, which was essentially like Pierre's, by 

 decomposition with water and titration with silver, was in detail as 

 follows : 



1 Ber. Deutsch. chem. Gesell., 16, 3014. 1883. 



