ABSTRACT OF PROCEEDINGS. liii. 



On the motion of Dr. Walter Spencer seconded by His 

 Honor Judge Docker, a hearty vote of thanks for his 

 services as President, and best wishes for his future wel- 

 fare was carried with acclamation. Mr. Burge returned 

 his thanks. 



THE FOLLOWING PAPERS WERE READ : 



1. "The Approximate Oolorimetric Estimation of Nickel 

 and Cobalt in presence of one another," by R. W. 

 Ohallinor. (Communicated by Acting-Professor J. A. 



SCHOFIELD, A.R.S.M., F.I.C.) 



Use is made of the complementary colours of Ni and Co 

 solutions apparently first observed by Maumene about 

 1851, and adapted to the mutual estimation of Ni and Co 

 by Winkler in 1866. Winkler used solutions of varying 

 strengths and in most cases much stronger than that used 

 by the author. It is intended that the method should be 

 applied to the solution of the weighed Ni and Co deposited 

 by electrolysis. The mixed metals are dissolved in HN0 3 , 

 the solution evaporated to about 5 cc. to remove the 

 greater part of the acid, diluted to a definite volume, 

 and a fraction taken containing about '05 grams of the 

 mixed metals. Standard Ni (N0 3 ) 2 ('01 gram Ni per cc.) 

 or Co (NO 3 ) 3 ('003 gram per cc.) solution is then added 

 until the colour matches a neutral tinted solution contain- 

 ing *012 grams Co and *038 grains Ni as nitrates in 50 cc; 

 both solutions are contained in 50 cc. in Nessler tubes 

 10*9 cm. high from cc. to 50 cc, and brought finally to 

 the same dilution, the colours being compared by looking 

 vertically down the tubes. A better method is to add a 

 measured amount of the standard Ni solution till green and 

 then to titrate back with the Co solution. The maximum 

 error with the latter method is about '0007 grams on '05 

 grams of the mixed metals, i.e. about 1*5°/°. 



