A Comprehensive Treatise on Inorganic and Theoretical Chemistry

122 INOKGANIC AND THEORETICAL, CHEMISTRY
and for the thermoelectric force of platinum against the other platinum metals,
vide infra.
A. Walcker, and L. Nobili observed that in cold water hot platinum is positive
against cold platinum, also in sulphuric acid (1 : 2), in soln. of sodium chloride
(1 : 10 and 1 : 100), but negative in soda lye. F. C. Henrici said that the hot metal
is positive in soln. of sulphuric or nitric acid, ammonium chloride, potassium iodide,
cupric chloride, mercuric nitrate, stannic chloride, and ferric chloride or sulphate ;
and negative in "water, hydrochloric acid, potassium hydroxide, chlorate, carbonate
or sulphate, sodium carbonate, copper sulphate, silver nitrate, ferrous chloride or
sulphate, acetic acid, oxalic acid, very dil. soln. of sulphuric or nitric acid, barium
chloride, mercuric chloride, manganous chloride, and potassium ferrocyanide.
Observations were made by M. Faraday, A. Voller, H. Wild, A. C. Becquerel, Gr. Gore,
B. Kaniewsky, and R. Kremann and co-workers. E. Bouty studied the thermoelectric
force of platinum against platinic chloride. The thermoelectric force against
some fused salts and glass "was studied by R. Bottger, T. Andrews, and W. G. Hankel.
The Peltier effect was studied by E. Edlund, 22 and H. Jahn. A. E. Caswell
gave 0-85. P. W. Bridgman measured the Peltier effect, JP X 10 6 joules per coulomb,
with platinum, uncompressed metal and metal compressed at p kgrms. per sq. cm.,
and found :
P 0° 20° 40° 60° 80° 100°
f 2,000 . . 7-7 10-3 12-8 13-7 12-7 lO-l
PXlO^ 6,0OO . . 23O 32-2 37-0 37-6 36-6 351
(^12,000 . . 44-8 64-8 76O 76-6 72-3 64-9
or Pxl0«=( —3-092—O-O26680)(0-|-273) volts for one sample of platinum against
lead, and for another specimen, Px 10 6 =( —1-788—O-O3460-}-O-O312602)(0-|-273)
volts. J. Gill also measured the Peltier effect between platinum and dil. sulphuric
and nitric acids, and soln. of sodium chloride and potassium bromide and sulphate.
According to O. Berg, the Thomson effect is negative, and changes only a little
with temp., and he found that crXl0 6 =8-79 to 9-69. Lord Kelvin observed that
the heat flows from the warmer to the colder parts in the direction of the current.
The subject was studied by E. H. Hall, C. Benedicks, W. Konig, F. P. Ie Roux,
H. Haga, and J. Weiss. According to P. W. Bridgman, o- X 10«--=0-02668(0+273)
volts per degree for one sample of platinum against lead, and o-XlO 6 = — 0-0346
—O-O32520(0+273) volts per degree for another sample. For a platinum couple
made of uncompressed metal and metal compressed at p kgrms. per sq. cm., the
Thomson heat effects,