172 A. W. Wright—G@ases contained in Meteorites. 
temperatures employed, as has often been observed in expeti- 
ments with meteorites. 
t has been pointed out by astronomers that on —s 
the mean distances of the asteroids in a series, there are foun 
to be certain gaps in the list. as if some members were wanting. 
Now it is further found that the periodic times of these missing 
bodies stand in a simple relation to the time of Jupiter's revo- 
: ' ‘i 
Changes of temperature in a mass of considerable absorptive 
and low conducting power must give rise to powerful stresses, 
the action may be sufficiently energetic to cause the splitting 
up of the bodies themselves” The disruptive action requisite 
to separate a mass from the principal body entirely, and so as 
not to return, would be less as the mass of the body is smaller, 
and would, for a mass no larger than some of the asteroids, be 
