( 93 ) 



4. As regards the extent of tlie cleetrolylie dissoeialioii we ubscrve 

 that altliongli we have not siiceeeded in (U'lei-niinijig the anionnt ^) 

 tlie experiments liave shown that il is xcrv small. Its exiytenee, 

 moreover fnrther strengthens the conclusion to whicii the experiments 

 have led, namelv that a certain proi)<)rtioii of tlie water remains in 

 combination with the nickelsulphate. 



5. The ex[)erinients have been made as before, in the first i)lace 

 witii the hydrates NiSO^, 6 aq. and Ni S()^, 7 a({. ; a single exi)erimenl 

 was made with Ni SO^, 3 H,() 3 CH, OH. 



The manner in which the calculation was conduclcd will be seen 



from the following example: ,v represents here the number ol" mols. 



of water abstracted from the hydrate '). 



59.i) gr. (^H30H, 0.7723 gr. NiSO, 6 aq. 



(mol. elevation of b. p. of metli. ale. 8.8. Mol. weight NiS( )^ H a(i. == 2(32) 



observed elevation of boilijig i)oint =:; 0MG5 



Calculated elevation of boiling point supposing all the water 



. , . , . 0.7723 100 



had remamed m combmation - — X X 8.8 =: 0°.043 



262 59.9 _____ 



elevation of b. p. caused by water delivered l)y the salt = 0°.122 



0,122 



With this corresponds a quantity of water in solution of-* V„. 



^ ^ ^ 0,281 '" 



The abstraction per mol. of dissolved hydrate is, therefore, 



0,122 262 1 



X = X 0,599 X X — = 4.9 mol. H 0. 



0,281 ^ -^ 0,7723 18 ^ ^ . ^• 



The results of the following experiments were : 



Methylalc. NiS04 6aq. Elevation of b. p. .v. 



58.5 gr. 0.G08 gr. 0".143 5.4 



60.5 » 0.G94 » 0.1 4G 4.9 



G0.5 » 0.551 » 0.125 5.3 



Average from four experiments 5.1 



NiSO^, 7 aq. gave the following results: 



1) See next communication. 



~) Strictly speaking, the elevation of the boiling point caused by liie same 

 amount of water will be modified in a slight degree by dissolving the salt in 

 melhylalcoliol. This influence was not taken into account ; the slight amount of 

 electrolytic dissociation (see next article) was also disregarded. 



