A Comprehensive Treatise on Inorganic and Theoretical Chemistry

PLATINUM 81
Observations were also made by W. J. Beekman and F. W. Oudt, P. Drude,
I. C. Gardner, P. R. Gleason, A. de Gramont, E. Hagen and H. Rubens, R. Hamer,
F. Henning, E. O. Hulbert, J. Konigsberger, K. Lauch, W. Meier, W. A. Miller,
A. H. Pfund, H. de la Provostaye and P. Desains, G. Quincke, P. Rouard, E. Schuch,
H. E. Strauss, H. von Wartenberg, and W. Wien. E. P. !Lewis and A. C. Hardy
studied the absorption in the ultra-violet. A film of thickness O0623 cm. was
found by J. Moser to be a poor reflector. P. R. Gleason observed a marked reduction
in the reflecting power with increasing age. C. Fery said that a surface of
platinum black at 100° reflects 18 per cent, of the incident rays ; K. J. Angstrom
obtained only 0-82 to 1*25 per cent, for different regions of the spectrum ; and
T. Royds gave for platinum black deposited in 15 and in 3 mins., respectively,
JF?i and R% :
A 0-8 8-7 25-5 51fx
R1 . . . 0-17 0-59 0-93 1-1 per cent.
2?a . . . 1-3O 5-70 7-08 7-4
F. Limmer said that crystals of platinum obtained by the action of cupric chloride
on spongy platinum had an unusually strong reflecting power. P. Desains studied
the reflection of heat rays from polished platinum ; the selective reflection 1 WaS
studied by H. Rubens ; the changes of phase in the reflected light, by H. Kath,
and J. Patterson ; and the relation between the electrode potential and the optical
constants, by V. Freedericksz.
K. Forsterling and V. Freedericksz gave for the index of refraction, for light
of wave-length A :
A . . . 1OO 1-52 1-97 3-29 3-41 4-65/z
ft . . . 3-42 4-71 5-92 7-5O 8-82 10-9O
and W. Meier :
A . 257-3 274-9 325-5 361-1 398-2 441-3 508 QGS1X1X
fx . 1171 1-294 1-275 1-375 1-735 1-398 2-285 2-913
Observations were made by E. van Aubel, H. Barvir, E. Dershem, P. Drude,
W. Eisenlohr, E. Hagen and H. Rubens, S. Haughton, A. Kundt, K. Lauch, M. Laue
and F. F. Martens, G. Quincke, P. A. Ross, D. Shea, W. Voigt, H. von Wartenberg,
and C. Zakrzewsky. B. Pogany found for films of thickness d, the following indices
of refraction, /JL :
d . 1-4 2-6 4-9 7O 11-7 16-8 20-OfXfx
fx . 3-45 3-17 2-65 2-25 216 2-1O 204
J. H. Gladstone calculated 26-01 for the refraction equivalent of platinum in
PtCl4 ; N. Kurnakoff, 11-9 to 16-7 for platinum in PtCl2.4NH3 ; 161 to 21 0, in
Pt(N03)2Cl2.4NH3 ; 24-7, in K2PtCl4 ; and 37-7, in Na2PtCl6.
The birefringence was studied by A. Kundt, and F. Kaempf. H. Rumpelt
said that the double refraction cannot be regarded as a consequence of mechanical
deformation. J. Thibaud and co-workers observed no evidence of the polarization
of a beam of electrons by crystal-reflection. J. B. Nathanson studied the interference
fringes of thin films. D. F. J. Arago observed that the light emitted by
glowing platinum is partially polarized vertically to the plane of emission. Measurements
of the polarization were made by H. de la Provostaye and P. Desains, W. von
Uljanin, K. Forsterling, A. Lallemand, R. A. Millikan, M. Laue and F. F. Martens,
H. Knoblauch, W. Moller, and C. W. Waidner and G. K. Burgess. W. von Uljanin
found that platinum exhibits a feeble dispersion in the region 2^i, and the subject
was studied by C. Zakrzewsky, P. Zeeman, J. Bauer, and B. Dessau ; and the
transmission of light by thin films, by H. Kienle and H. Siedentopf.
M. Cau 3 discussed the magneto-optical effect, and B. Pogany, the Faraday
effect with spluttered films.
According to H. F. Weber, 4 the ratio of the emissivity of platinum to that of
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