_______________________________________________________

__________
|
|  The temperature sinks
Substances to be mixed in parts by   |-------------------------
weight.                 |    from    |     to
_______________________________________|____________|_______

_____
|            |
1.   Water.                       1     |   +10 deg.  C.  |   -15.5 deg.  C.
Ammonium nitrate.           1     |            |
2.   Dil. hydrochloric acid.     10     |   +10      |   -17.8
Sodium sulphate.           16     |            |
3.   Dil. hydrochloric acid.      1     |   +10      |   -16
Sodium sulphate.            11/2    |            |
4.   Snow.                        1     |   + 0      |   -32.5
Sulphuric acid.             4     |            |
Water.                      1     |            |
5.   Snow.                        1     |   — 7      |   -51
Dil. sulphuric acid.        1     |            |
6.   Snow.                        1     |   -23      |   -49
Dil. nitric acid.            1/2    |            |
7.   Snow.                        1     |     0      |   -17.8
Sodium chloride.            1     |            |
8.   Snow.                        1     |     0      |   -49
Calcium chloride.           1.3   |            |
9.   Snow.                        1     |     0      |   -33
Hydrochloric acid.          0.625 |            |
10.  Snow.                        1     |     0      |   -24
Sodium chloride.            0.4   |            |
Ammon. chloride.            0.2   |            |
11.  Snow.                        1     |     0      |   -31
Sodium chloride.            0.416 |            |
Ammon. nitrate.             0.416 |            |
_______________________________________|____________|_______

_____

* * * * *

THE APPLICATION OF ELECTROLYSIS TO QUALITATIVE ANALYSIS.

By CHARLES A. KOHN, B.Sc., Ph.D., Assistant Lecturer in Chemistry, University College, Liverpool.

The first application of electrolysis to chemical analysis was made by Gaultier de Claubry, in 1850, who employed the electric current for the detection of metals when in solution.  Other early workers followed in this direction, and in 1861 Bloxam published two papers (J.  Chem.  Soc., 13, 12 and 338) on “The application of electrolysis to the detection of poisonous metals in mixtures containing organic matters.”  In these papers a description is given of means for detecting small quantities of arsenic and of antimony by subjecting their acidulated solutions to electrolysis.  The arsenic was evolved as hydride and recognized by the usual reactions, while the antimony was mainly deposited as metal upon the cathode.  The electrolytic method for the detection of arsenic, in which all fear of contamination from impure zinc is overcome, has since been elaborated by Wolff, who has succeeded in detecting as little as 0.00001 grm. arsenious oxide by this means (this Journal, 1887, 147).