on Chemical Equivalence. 173 



and the temperature observed. The precipitate -was then fil- 

 tered (with the help of an aspirator), and washed with cold 

 and afterwards with hot water until the washings showed no 

 trace of nickel; the precipitate was then dissolved in pure 

 hydric sulphate, evaporated to dryness, ignited, and weighed 

 as nickelous sulphate. The results obtained in these experi- 

 ments are given in the following table : — 



Table II. 



Sodic carbo- 

 nate taken. 



Nickelous 

 salt taken. 



Nickelous salt -.-. , , ,J 



1 , , . • v Nickelous salt 



(obtained) ( ca i cu i ate d) Temperature, 

 precipitated. ^ recipitatec { P 



grm. 

 0-37151 



grm. 

 01050 

 03100 



0-5000 

 0-7100 

 1-0000 



grm. 

 01015 

 0-1912 

 0-4084 

 0-5103 

 0-5550 



•1192 

 •2139 

 •3967 

 •4856 



•5745 



5-6 C. 



4-8 



73 



4-8 



56 



(2) Nickelous Salt constant. Sodic Carbonate varies. — This 

 series was conducted in the manner of (1) ; only there was 

 always the same volume of nickelous sulphate measured out, 

 viz. 100 cub. cent. To this was added enough distilled water 

 to make, along with the volume of sodic carbonate to be added, 

 10 cub. cent. The results thus obtained are given in the fol- 

 lowing table: — 



Table III. 



Sodic carbo- 

 nate taken. 



grm. 

 0-057151 

 0-114302 

 0285755 



0-571510 



Nickelous 

 salt taken. 



grm. 

 1-000 

 1-000 

 1-000 



1-000 



Nickelous salt -.-. , , .. 



(obtained) ^ ckelous salt - 



precipitated 



(calculated) 

 precipitated. 



grm. 

 0-0300 

 0-0798 

 0-2311 



0-5485 



grm. 



011393 

 00810 

 0-2242 

 0-54.50 



Temperature. 



7-SC. 

 8-1, 



7-9 

 7-9 



(3) Manganous Salt varies, Sodic Carbonate constant. — The 

 manganous sulphate was measured out, the solution made up 

 to 100 cub. cent, with distilled water, and 10 cub. cent, of 

 sodic carbonate solution added ; the mixture was then stirred, 

 and the precipitate filtered off, washed, and dissolved in pure 

 hydric chloride. The manganese was estimated as pyrophos- 

 phate. The results were as follows : — 



