Relations of the Atmosphere, 361 
sandths of that of the earth, the volume of the ocean being 
very much less. There is no known mass of cooled rock 
which has not a greater porosity than is represented by these 
figures, so that the conclusion seems inevitable that, with the 
The hypothesis that interstellary space is filled with an 
attenuated matter which, in a more condensed form, constitutes 
oe atmosphere and the waters of our own and other worlds, 
Simpler forms of matter by a process of cosmical chemistry. 
A similar view was a few months later advang cd by Mr. 
Lockyer, who reiterated and enforced these suggestions, show- 
ing that the chemical elements make their appearance in the 
Cooling stars in the order of their vapor-densities—and more- 
Over connected these considerations with the conjectures of 
mas as to the probably compound nature of the so-called 
. ‘uni : ogi le systéme planctaire du 
tl, Bull So, al de He 1860-1, yl sy 20% tonal by to pr 
®nt writer for this Journal, II, xxxiii, p. 36. 
t Popular Science Monthly, Jan., 1873, vol. ii, p. 32. 
