A Comprehensive Treatise on Inorganic and Theoretical Chemistry

22O INORGANIC AND THEORETICAL CHEMISTRY
dius said that the pale yellowish-white alloy is quite malleable, takes a high polish,
and is equal to copper in fusibility, and to nickel in magnetic power.
N. S. Kurnakon" and V. A. Nemiloff observed no evidence of the formation of a
chemical compound of nickel and platinum on the f.p. curve, Fig. 59. The alloys
1800
1700 [
1600
13U0
20
Atnmii
40 GO 80 100
pel cent of platinum
Fro. 59.—The Freezing-point
Curves of the Ni-Pt Alloys.
form two types of solid soln., one with less and the
other with more than 2O at. per cent, of platinum.
The Brinell's hardness curve is shown in Fig. 60—vide
Table IV. ; and the electric resistance and temp,
coeff. between 25° and 100°, in Fig. 61. W. C. Heraeus
found that by heating alloys with 8 to 15 per cent,
of platinum to 800°, there is only a slight loss in tensile
strength, and elasticity. C. Barus measured the sp.
electric resistance and its temp, coeff. F. E. Carter
said that a 10 per cent, alloy has a resistance of 18O
ohms per million ft., and a 5 per cent, alloy, 140 ohms
per million ft., and a temp, coeff. of 0*00189 per degree
between 0° and 1200°. M. Hartmann and M. Braun,
and J. Wurschmidt measured the thermoelectric force ;
IJ. Neerl, C. Manders, F. W. Constant, the magnetic
properties ; and A. B. Jones, the photoelectric effect. K. Helouis noted that the
alloys resist oxidation when heated in air. H. Remy and H. Gonnington studied
the catalytic effect in the hydrogen-oxygen reaction. Gr. Tammann's study of the
action of gold chloride, nitric acid sp. gr. 1-44, fuming hydrochloric acid, soln. of
copper chloride, ferric chloride, ammonium sulphide, and sodium polysulphide showed
that the reactions are limited with alloys having up to 25 per cent, of platinum.
A. Gawalowsky said that the nickel-platinum alloy, known in commerce as platnik,
0 20 40 60 80 100
Atomic per cent of platinum
Fio. 60.—The Hardness of the
Ni-Pt Alloys.
0006
20 40 60 80 100
Atomic per cent, of platinum
Fio. 61. The Electrical Resistance and Temperature
Coefficient of the Ni-Pt Alloys.
can be used as a substitute for platinum in analytical operations. K. Janecke
studied the ternary systems involving the platinum-nickel-copper alloys ; and
the platinum-nickel-silver alloys. W. and R. Borchers prepared a platinumnickel-silver-chromium
alloy ; H. Bush, a platinum-nickel-silver-tin alloy ; and
W. and R. Borchers also prepared some more complex alloys. E. Janecke
studied the ternary system, involving the platinum-nickel-gold alloys ; and
the platinum-nickel-iron alloys. W. and R. Borchers described a platinumnickel-cobalt-chromium
alloy, and also a platinum-nickel-cobalt-chromiummolybdenum
alloy.
According to F. E. Carter, 21 ruthenium hardens platinum to about the same
extent as does osmium. The limit of workability is about 10 to 15 per cent, of
ruthenium. The Brinell's hardness of the annealed alloy, with 10 per cent, of
ruthenium, is 210—vide Table IV—and its electrical resistance, 245 ohms per
million ft. Ia. Holborn and A. L. Day measured the thermoelectric force of a