DR. A. SCOTT ON THE COMPOSITION OF WATER BE, VOLUME. 
567 
union was never admitted to ray mea,suring vessel, amongst other advantages, render 
my results more worthy of confidence than his. The means adopted by him for 
detecting any impurity are unable to detect such small amounts of foreign gas as 
were not only easily detected but measured by my method. As long as the bubble 
could be seen it could be measured, and this, as measured, was always a maximum. 
His excess over 2 volumes is just one-tenth part of what I find. 
The value for the ratio found by Leduc^ from his determinations of the densities of 
hydrogen, oxygen, and the detonating gas from the electrolysis of strong potassium 
hydrate solution, agrees far more nearly with my value, which it exceeds somewhat, 
being— 
2'0037. 
I do not think, however, that this method can compare in accuracy with a direct 
method, even if it be proved that the detonating gas so prepared unites completely 
without any residue whatever of either oxygen, hydrogen, or foreign gas. 
There is but little doubt that the carbon in Morley’s hydrogen is due to acetates 
in his potassium hydrate giving ethane on electrolysis, some of which, although 
evolved at the opposite pole, being soluble to a certain extent in wmter, will find its 
way into the hydrogen. It is well known that potassium hydrate, purified by 
alcohol, is useless for gas analysis.! 
The values for the ratio of the volumes are, therefore, 
Moeley.2’00023 : 1, 
Leduc .2'0037 : 1, 
Scott . 2-00245 : 1, 
and for densities— 
Lord Eayleigh . . . . 15-882, 
Leduc. 15-905. 
Combining my value with that of Lord Eayleigh, we get for the atomic weight 
of oxygen— 
1 5-862, 
a number almost identical with that of— 
and with 
Dittmar '. . . . 
Cooke and Etchards 
= 15-866, 
= 15-869. 
Combining Leduc’s two values, we get for the same— 
15-876. 
* ‘ Compt. Renclus,’ August 8, 1892. 
t Hempel’s ‘Gas Analysis,’ Dennis’ Translation, p. 115. 
