Page:Outlines of Physical Chemistry - 1899.djvu/14

 ADDENDA

1. Add to first footnote on p. 46 : — Glass flasks and tubes (Dewar tubes) constructed on the same principle are also used.

2. Add to § (c) on p. 97 : — We now know a few other sub- stances active both in solution and in the crystalline state: rubidium tartrate, caesium tartrate, cinchonine antimonyl tartrate, zinc bimalate, patchouli camphor, and one or two more substances.

3. Addition to the method of determining the conductivity of electrolytes, pages 197-199 : — Stroud and Henderson (* Phil. Mag.,' 43, 19) have invented a method of measuring the con- ductivity of electrolytes by direct currents (30 volts) in which the effects of polarisation are eliminated by introducing into each of two arms of a Wheatstone bridge cells containing different lengths of solution. In the arm containing the shorter cell there is a resistance in series with this cell, which in the position of equilibrium is equal to the difference in the lengths of the electrolyte in the two cells.

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