Bayley — On Colour Relations of Nickel and Cobalt. 133 



tralize this, 18 grams of ammonia -vrere required to be added to a 

 litre of the commercial carbonate solution. This was furnished by 

 61-7 c. c. of ammonia solution (of sp. gr. -880), 



I next endeavoured to determine whether the nature of the salt 

 of nickel or cobalt has any effect on the reaction. For this purpose 

 the following solutions were prepared : — 



Co CL 1 c. c. 



= -00125 grm. 



Co 



M CL 1 c. c. 



= -0025 grm. 



Ni 



M(N03)o 1 c. c. 



= -0025 grm. 



M. 



M SO4 1 c. c. 



= -0025 grm. 



m 



Co (Is^Oa). 1 c. c. 



= -00125 grm. 



Co 



Co SO4 1 c. c. 



= -00125 grm. 



Co 



The method of proceeding was as follows : — In each of five 

 cylinders 25 c. c. of the standard solution of cobaltous chloride were 

 placed ; to the first cylinder 39 c. c. of the solution of nickelous 

 chloride were added ; to the second cylinder 39-25 e. c, and so on ; 

 40 c. c. of nickelous chloride being added to the fifth cylinder. Each 

 cylinder was then made up to 100 c.c, and 25 c. c. out of each 100 

 c. c, were placed in a second series of cylinders. To each of the second 

 series neutral ammonium carbonate (25 c. c.) was added, and then 

 sufficient water to make 150 c. c. The results are expressed in the 

 following Table : — 



Cylinder. 



Co used. 



Ni used. 



Colour. 



Ratio of 

 Ni to Co. 



(1) 



•03125 grm. 



•09750 grm. 



purple. 



3^12 



(2) 



■03125 ,, 



•098125 „ 



slightly purple. 



3-14 



(3) 



•03125 •,, 



•098750 ,, 



between 2 & 4. 



3-16 



(4) 



•03125 ,, 



•099375 „ 



slightly blue. 



3^18 



(5) 



•03125 „ 



•10000 ,, 



blue. 



3^20 



In two experiments, using in the first solutions of Co CI3 and 

 M SO4, and in the second solutions of Co CI3 and M (1^03)2, I obtained 

 exactly the same results, so that the foregoing Table expresses the 

 results of these experiments. • Subsequently experiments were made 

 with the same quantities of the metals in the following combinations, 

 Co (]S'03)2 with M SO,, M (^03)0 and M CL Co SO4 with M (NOs)^, 

 Ni SO4 and M Clo. 



The results of these latter experiments were exactly the same as 

 those of the first experiments, so that the Table does equally well to 

 express them also. 



If the cylinders, after the addition of the ammonium carbonate, be 

 allowed to stand, the differences of tint disappear in a few hours, and 

 a uniform deep purple red tint is produced. This is caused by the cobalt 



