484 



SMITHSOXIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



The percentage of platimim in the platinbromide combines with Hal- 

 berstadt's figures as follows : 



Halberstadt 25.915, ± .0040 



Archibald 25.928, ± .0015 



General mean 25.927, ± .0014 



Several other ratios, given in diverse forms by Archibald, are also 

 capable of consolidation. The ratio between silver bromide and potas- 

 sium platinbromide, reduced to uniform type, that is, to AgBr : KoPtBrg : : 

 100 : X, becomes — 



2 AgBr series 400.932, ± .0096 



4AgBr series 400.932, ± .0100 



Genera] mean 400.932, ± .0069 



For the ratio Ag: KoPtBrg : : 100 : x we have — 



2Ag series 697.940, ± .0170 



4Ag series 697.920, ± .0204 



General mean 697.936, ± .0131 



