TRANSACTIONS OF SECTION B. 



491 



Substance in Solution 



IlgL(KI), 



HgCl22(NH,Cl).3H,0 

 HgBr,2(NH,Br).3H,0 



IIgCy„.NH,Cl . . 



AIK(S0,)„.12H,p 

 Zn3Cu(SO^),H20 . 



Nucleus added 



KI . 



Result 



Active 

 Inactive 



Active 



NaNH,HPO^,4H30 . 



NaNH,HAsO,.4H,0 



HgBr,2(NH,Br).3H„0. 



HgClj (prismatic) . . 

 NH^Cl 



HgCvo 



NH.Ci 



Experiments with Douhle Sulphates. 



AL3(SO,).18IT„0 . 



ZnS0^.7H.O . . . 

 CuSO^.SHjO . . . 



Experiments with Douhle Phosphates and Arseniates. 



luactive 



Active 

 Inactive 



Active 



Inactive 

 Inactive 



Active 

 Active 



Na.HP0,.12H.,0 

 (NH;)oHPO, ." . 

 (NHJHoPO, . . 



Na^P.O, . . . 



Na„HAsO,12H„0 



(NH,)„HAsO^.Aq2 





KNaH/jp64Aq 

 K3Na32(H,CeO,) 



MgNall.Cp, 



Experiments with Certain Organic Salts 



Na,H,C,Os • 



Na,II,Cp, . 



MgHcH.Cp,) 

 Na3H,C,0, . 



Inactive 



Active 



Active 



Inactive 



From these tables it -will he seen tliat, in the case of the double chlorides, 

 bromides, and iodides, the salt of the heavy metal invariably caused the crystallisa- 

 tion of the double salt, whereas the constituent containing the alkali-metal had no 

 action. It was, however, impossible to determine whether the salt causing crystal- 

 lisation did so by first inducing the deposition of the salt analogous to itself in the 

 solution; experiments are being carried out to endeavour if possible to detei-mine 

 the primary action which takes place. It is, however, a somewhat dlfficidt one to 

 examine. . • j • 



It may also be observed that when the mercuric chloride or bromide existed in 

 the nucleus in its true prismatic form, crystallisation at once took place, but that 

 when its deposition from its solution took place at a higher temperature the results 

 were various. On examining this point he finds that the crystalline form of the mer- 

 curic chloride and bromide change when so deposited, which may readily account 

 for the alternation in those cases. The- crystalline form also of the double salt is 

 more nearly allied to the form of the heavy metallic salt than to the constituent 

 containing the alkali-metal. In the case of the double cyanide and chloride, how- 

 ever, there is a distinct difierence from the halogen salts employed in the first- 

 mentioned experiments, both components producing the crystallisation of the 

 double salt. 



