174 



Messrs. Mills and Bicket's Researches 



Table IV. 



Sodic carbo- 

 nate taken. 



Manganous 



sa.lt taken. 



X, 



Manganous 



salt 



(obtained) 



precipitated. 



y- 



Temperature. 



grm. 

 0-57151 



grm. 

 0-1050 

 0-2000 

 0-5000 

 0-7100 

 1-0000 



grm. 

 0-1039 

 01969 

 0-4894 

 0-6748 

 0-7500 



9-3 C. 



9-3 

 101 

 10-1 



9-7 



(4) Manganous Salt constant, Sodic Carbonate varies. — This 

 series was conducted like series (2). The washed precipitate 

 was dissolved in hydric chloride and the manganese estimated 

 as pyrophosphate. The results are given in the following- 

 table"':— 



Table V. 



Sodic carbo- 

 nate taken, 

 .r. 



Manganous 

 salt taken. 



Manganous 



salt 



(obtained) 



precipitated. 



y- 



Manganous 



salt i 

 (calculated) Temperature, 

 precipitated. 



QDO ^H CI O 



6666 



grm. 

 1-0000 

 1-0000 

 1-0000 

 1-0000 



grm. grm. 

 0-0400 0577 7-6 C. 

 0-1145 -1188 76 

 0-3558 -3261 78 

 0-7592 -7797 9-2 



Discussion. 



Conjoint Precipitability. — If n represent nickelous sulphate 



taken, and v the carbonate (calculated to sulphate) obtained 



from it by precipitation, then cj> in the expression ?i = (f>v is the 



precipitability. Our experiments (Table I.) satisfy the equation 



<£ = 98570 + -61438 n (1) 



(which is deduced from all of them), with a probable error of 

 •055284 for a single determination, or -018428 for nine de- 

 terminations. 



Similarly, in the case of manganous sulphate (Table II.), 



^ = 3-0881-l-7203m ; (2) 



with probable error amounting to '088893 and -029631 respec- 

 tively. In both cases, therefore, the precipitability is a linear 

 function of the mass. The second constants in equations (1) 

 and (2) present an interesting relation, closely resembling that 



