A Comprehensive Treatise on Inorganic and Theoretical Chemistry

192 INORGANIC AND THEORETICAL, CHEMISTRY
furnished 195-191 from the ratio (NH4)2PtCl6 : Pt ; 195-216 from 6AgCl : Pt ;
195-245 from 6AgCl : (NII4J2PtCl6 ; 195-213 from 6Ag : Pt ; and 195-241 from
6Ag : (NH4)2PtCl6. The analyses of ammonium bromoplatinate furnished 195-206
from the ratio (NH4J2PtBr6 : Pt ; 195-214 from 6AgBr : Pt ; 195-242 from
6Ag : (NH4)2PtBr6 ; 195-220 from 6Ag : Pt; and 195244 from 6Ag : (NH4)2PtBr6.
The best representative value from E. H. Archibald's determinations is 195-22.
The international standard for the best representative value of the atomic
weight of platinum for 1931 is 3 95-2, and representative values were discussed by
F. W. Clarke, L,- Meyer and K. Seubert, J. I). von der Plaats, W. M. Watts,
T. W. Richards, W. A. Noyes, G. D. Hinrichs, and A. Vurtheim.
C. T. Heycock and F. H. Neville 4 discussed the molecular state of platinum
in alloys with cadmium, lead, and bismuth ; and E. O. von Lippmann estimated
30 to 4O atoms per molecule. W. C Roberts-Austen added that experiments on
the diffusion of platinum suggested that the molecules are more complex than those
of silver, or gold. The relations between the elements and their at. wts. were discussed
by G. Osann, M. Gerber, F. Sanford, and C. A. Martius ; the relations
between the at. wts. and the affinities of the elements, by E. Donath and J. Mayrhofer,
P. Pfeiffer, and F. Gramp ; between the at. wts. and the heats of reaction,
by M. Berthclot ; the relations between the at. wts. and the elastic constants,
by J. Johnston ; and the relations between the at. wts. and the colour of the
elements, by M. C. Lea.
The atomic number of platinum is 78. E. Amaldi, 5 A. J. Dempster, B. Fuchs
and H. Kopfermann, H. Kopfermann and K. Krebs, B. Jaeckel and H. Kopfermann,
F. Allison and E. J. Murphy, and B. Veiikatesachar and L. Sibaiya reported
that platinum has five isotopes of atomic mass 192, (193), 194, 195, and 196 with
the relative abundances, for the 192, 194, 195, and 196 isotopes are, respectively,
2, K), 13, 16 ; J. H. Bartlett studied the subject. The atomic disruption of
platinum by the bombardment of