286 



-/. C. Blake — Colors of Allotropic Silver. 



Table I. 

 A. Water Solution of Silver Nitrate. 



Reagents. 



Opaque 

 precipitate, 

 color in re- 

 flected light. 



Solutions, color in transmitted light. 



Blue. 



Red, 

 dilute. 



Red, con- 

 centrated. 



Yellow. 



9. 

 10. 



11. 

 12. 



13. 

 14. 

 15. 

 16. 



17. 



18. 



19. 

 20. 



21. 

 22. 



23. 

 24. 



26. 



Formalin . . 



If large ex- 



Hot or 



On stand- 









cess, gray 



moderate 

 excess. 



ing 







Formalin + NHiOH... 



1 

 1 



Mirror 







If little 



ammonia : 



mirror 



Formalin + NaOH 





-1- 









Hydrazine hydrate 





+ 







If dilute, 

 mirror 



Hydrazine hydrate + ether.. 





-t- 







" 



Hydrazine hydrate + alcohol 





+ 









Hydroxylamine _ _ 





+ 









Hvdroxylamine sulphate + 



Hydroxyl- 









If little 



NH.OH 



amin sulph. 



in excess, 



gray 



+ 







ammonia ; 

 mirror 



Phenylhydrazine _ 





+ 









Ether + FeSO^ (trace) 





Add ether 

 first, mir- 

 ror 









Chloroform + NH,OH 





+ 









Chloroform + FeSO 4 -- 





Soon 



changes to 



AgCl 









Carbon bisulphide + FeS04 . 





-f- 









Hypophosphorus acid 





+ 



Unstable 





Unstable 



Phosphorus acid 





-1- 



+ 







Phosphorus trichloride + 













NH4OH 





-}- 









Phosphorus in ether 











+ 



Phosphorus in ether + 













NH4OH 





4- 









Sodium citrate + FeS04 





+ ■ 









Rochelle salt + FeS04 





+ 





If little 

 FeSOi w. 













prec, 

 turns red 





Rochelle salt + NaOH 





+ 



Turbid, 

 stable 







Sodium citrate + NaOH + 









Stable if 





FeSOi 









little 

 FeS04 









Rochelle salt + NaOH + 













FeS04 ---- 









(< 





Tannic acid + NH4OH or 









MiiTor, 



Mirror, 



XaOH. . . 









stable 

 Solution, 



unstable 



Tannic acid + NaOH + FeS04 













stable. 













mirror. 













unstable 





Sulphur dioxide _ - . 







White 

 prec, 













turns pink 







