•236 
THE VOYAGE OF H.M.S. CHALLENGER. 
the several quantities of potassium are all expressed in milligrams of K 2 0. For 
each of these latter quantities, as is seen, two numbers are given : the numbers under 
“old atomic weights ” were calculated by means of the set of atomic weights which I had 
used in mv potash determinations in the Challenger waters, viz., — K = 39, Cl = 35 - 5, 
Pt = 198, 0 = 1G. The numbers under “new atomic weights ” are calculated from Stas’s 
values for Iv and Cl, and Seubert’s for Pt, viz., — K = 39'13, Cl = 35‘454, Pt=194*83, 
0=16. 
From the following little table it is seen how the several ratios change when we pass 
from one set of constants to the other. 
Numerical Values calculated from 
New Factor 
Old 
New 
divided by 
Ratios. Atomic Weights. 
Atomic Weights. 
Old Factor 
, K -!, ) .... 0-63087 
0-63193 
1-00168 
KXL 
K.,0 
.... 0-47474 
0-48385 
1-0192 
K o° _ 0-19223 
0-19405 
1-0095 
PtCl fl K 2 
will now pass to the statement of the results : — 
Milligrams of K 2 0 present. 
Old 
New 
Synthesis. 
Atomic Weights. 
Atomic Weights. 
In the chloride of potassium, 
49-89 
49-98 
In the chloride of sodium, 
1-79 
1-82 
51-68 
51-80 
Analysis. 
I. In the crude chloroplatinate of potassium by calculation 
on the assumption of its being unmixed PtCl 0 K 2 , 
49-44 
49-91 
la. By calculation from the metallic platinum obtained 
therefrom, ..... 
49-08 
50-03 
II. In the pure chloroplatinate of potassium, 
47-78 
48-22 
II/i. Calculated from the metallic platinum therefrom, 
47-56 
48-48 
III.* In the filtrate from the crude chloroplatinate, 
3-78 
3-82 
IV. In filtrate from the pure chloroplatinate, 
0-38 
0-38 
Sum of II., III., and IV., . 
51-94 
52-42 
Excess over synthetical value, 
0-26 
0-62 
Bum of IIo, III., and IV., 
51-72 
52-68 
Excess over synthetical value, 
004 
0-88 
* Alkali mate into stdphate ; pota- ium extracted by sal-ammoniac form of Finkener’s method, as PtCl 8 K 2 . 
P’.jtin'im ot !.i !>< I therefrom 10-fi m grins. 503 mgrms. of K 2 0 The solution from this metal worked up according to 
* ' ’ l‘tt l t K, 'lain'd ■» lli'7 rngniis. - 378 mgrms. of K 2 0 Viy old atomic weights. This latter result adopted. 
