164 T. H. LABY. 
No. | taken | Cobalt Table I.—Cobalt. Cobalt | peror, 
in gms. 
1 | -004 | °2289 *2293 | +°0004 
2 | :004 | 2289 *2290 | +0001 
3 | none | ‘2289 -2287 | —-0002 
Ay) 92 -2289 | cobalt not completely removed by | :2253 | —-0036 
5 2 -2389 electrolysis. -2966 | - :0023 
6 | [2 °2289 | ditto,' ditto, ditto 2178 | -:0111] 
WANs *2289 *2221 | — ‘0068 
Si s2 "0229 "0235 | +0006 
OZ "0229 0238 | +0009 
10 | none | °0458 "0466 | +0008 
11 | none | '0229 0235 | +:0006 
1 This filtrate though electrolysed all night and for three hours with ‘8 ampéres still 
contained cobalt as was shown by passing sulphuretted hydrogen. 
Tron : R i 
No. | taken Nee Table II.—Nickel. pene Error. 
in gms. 
"004 | -2149 "2145 | — 0004 
‘004 | -2149 | ferric hydrate contained nickel *2123 | — -0026 
none | °2149 "2147 | - -0002 
2; °2149 | iron ppt. by PbO from boiling sol. 2114 | —-0085 
a4 *2149 | ditto, ditto, by PbO in the cold "2100 | —-0049 
"2149 | ditto, ditto, by PbO from boiling sol.| ‘2122 | —-0027 
none | *2149 | Ph added and removed as sulphate | ‘2155 | +°0006 
"4, °0430 0454 | +°0024. 
"4, "0430 0451 | +°0001 
none | ‘0430 0439 | +°0009 
none | ‘0219 6224 | +:0005 
oe 
KH OCU ON DO FW WH 
bo 
Conclusions. 
This method, requiring only one precipitation of the iron, 
though not so good as claimed by Field, is more accurate for 
cobalt than the basic acetate process; and as accurate for 
nickel—about 997 of the latter and rather more of the 
former being recovered. It can be very readily combined 
with the electrolytic determination of nickel and cobalt, 
(Gooch and Medway’ using a rotating cathode, have accu- 
rately determined nickel by electrolysis with a current of 
less than thirty minutes duration.) 
The author desires to thank Professor Liversidge for 
having given every facility for this research. 
+ American Journal of Science, 1903, xxv., p..50. 
