Influence of Atomic Weight. 475 



Percentage of 

 Mixture. decomposition. 



/'4BC] 3 +3CBr 4 10*121 



\4BBr 3 + 3CC1 4 89'97/ 



/SiCl 4 + CBr 4 12-461 



(SiBr 4 + CC1 4 87-54/ 



/TiCl 4 + CBr 4 43-611 



\TiBr 4 +CC1 4 57-39/ 



/4AsCl 3 +3CBr 4 71/78 1 



J4AsBr 3 + 3CCl 4 28-91/ 



/SnCl 4 + CBr 4 97-521 



lSnBr 4 +CC1 4 2-16/ 



From this it is seen that the higher the atomic weight of 

 the element (B, Si, Ti, As, Sn) united with CI, the more is 

 the CI replaced by the Br of the CBr 4 ; and the higher the 

 atomic weight of the element united with Br, the less will 

 that Br be replaced by the CI of the CC1 4 . 



Cross and Suguira (Chem. Soc. Journ. 1878, p. 405) haye 

 shown that the amount of in PbO replaced by the action of 

 the halogens at a high temperature is the greater the lower the 

 atomic weight of the halogen. 



Mills (Phil. Mag. [4] xl. p. 134 ; xliy. p. 343), from his 

 experiments on the action of POCl 3 on yarious nitrates, has 

 calculated the ratio (a) between the amount of and CI left 

 in the respective residues after distilling off the excess of 

 POCl 3 , and finds that, with one exception, this ratio in- 

 creases with the equivalent weight of the nitrate : thus 



P 2 Q - Equivalent 



CI ' weight. 



TIX0 3 8-76 265-3 



AgN0 3 5-48 169-9 



±Pb(NO s ) 2 5-17 165*6 



RbN0 3 2-38 147-4 



CsN0 3 2-21 (?) 195-0 



KX0 3 1-99 101-1 



NaXO s 1-70 85-1 



LiX0 3 1-61 69-0 



The Rate of Ethe rifle ation of Alcohols by Acetic Acid has 

 been determined by Menschutkin {Ber. cleut. chem. Ges. x. 

 p. 1728; xi. p. 1507) ; and he finds that the relative rate of 

 etherification diminishes as the molecular weight of the alcohol 

 increases : thus 



2K2 



