ON ELECTROLYTIC METHODS OF QUANTITATIVE ANALYSIS. 251 
rent passes through the resistance box R,, then to the block C,, and finally 
to the table A to complete the circuit. By placing the spanner between 
m, and the cup on the board A’ leading to the ampere-meter, mm’, the current 
is similarly completed through the ampere-meter, so that the reading is 
taken without stopping the current. The connections to the voltmeter will 
be clear from the diagram ; it is simply a branch from each of the circuits. 
The Determination of Antimony. By Cuartes A. Konn, Ph.D., BSc., 
and C. K. Barnes, B.Sc. 
Bibliography. 
Author Journal Year | Volume] Page Composition of Electrolyte 
Parodi, G., and Mas- | ina r ~ | {Ammonium tartrate. 
Gazinic A. | Zeits. anal, Chem. . 1879 18 587 ( Alkali sulphide. 
25 | Fattc ‘ { Hydrochloric acid. 
Luckow, C. ° | Zeits. anal. Chem.. | 1880 19 1 | Aikali sulphide. 
F Potassium oxalate. 
‘ ais | s . 
Classen, A., and Reis, Ber. . ° . | 1881 14 1622 | Alkali tartrate. 
M.A. ji : 
Ammonium sulphide. 
} Sodium sulphide. 
Classen, A. wae oe | ar om he .| 1884 17 2467 | | Sodium or potassium sulph- | 
{ hydrate. 
Classen, A., and Lud- | Ber. Be oe eS 18 1104 Sodium sulphide. 
wig, R. 
Brand, A... . . | Zeits. anal. Chem.. | 1889 28 581 Sodium pyrophosphate and 
: ammonium carbonate. 
Lecrenier,A. «» «. | Chem. Zeit. . . | 1889 13 1219 Sodium sulphide and sodium 
sulphite. 
Vortmann, G. ., - | Ber. Py 4 c 1891 24 2749 Sodium sulphideand hydrate 
as amalgam. 
Riidorff, F. . «| Zeits.angew.Chem. | 1892 — 3 Sodium sulphide, 
Classen, A. e . | Ber. 2 C .| 1894 Pig 2060 Sodium sulphide. 
The deposition of antimony from solutions of its sulpho-salts, as first 
suggested by Parodi and Mascazzini, and also by Luckow, has been espe- 
cially studied by Classen and his pupils. Classen finds that a sodium 
sulphide solution is best adapted for the deposition ; the reagent must be 
free from polysulphides, which, if present, are oxidised by hydrogen per- 
oxide. The deposition is effected in the cold solution with a current of 
15-2 c.c. of electrolytic gas per minute, and requires 10 to 12 hours. 
Nissenson states that 0:15 erme. of antimony can be deposited from a 
solution of the su!pho-salt in one hour by electrolysing the warm solution 
with a current of 0°5—1-0 ampere. 
Of other solutions ammonium tartrate has alone been stated to give 
accurate results, the deposits obtained from hydrochloric acid, potassium 
oxalate, and sodium pyrophosphate solutions not adhering sufficiently well 
to the dish to be of value for quantitative determinations. 
Experiments were accordingly restricted to the deposition from sodium 
sulphide and from ammonium tartrate solution. 
Deposition of Antimony from Sodium Sulphide Solution. 
A hydrochloric acid solution of antimony chloride, prepared from 
pure antimony, was employed for the experiments, the solution containing 
just sufficient acid to keep the chloride of antimony in solution. It is 
important to use pure sodium sulphide ; this was prepared from sodium 
hydrate purified by alcohol, in the usual way, and concentrated to a 
sp. gr. of 1°18, 
