494 T. C. CHAMBERLIN 



minerals commonest in meteorites, including iron, are lo, lo . 59, 

 12 .49, 14.69, 15.87, 16.18, 16.49, 16.70, 18.38. These are to be 

 compared with the square roots of representative molecules that 

 are not held by the atmosphereless bodies. We may take the 

 molecules of oxygen and nitrogen as representing these, the square 

 roots of their molecular weights being 5.66 and 5.2, respectively. 

 The high temperatures at which alone the stony and metallic sub- 

 stances occur in working quantities enter vitally into the case.^ 

 Making requisite computations, it appears that these heavier 

 molecules would not be held under genetic conditions by the four 

 lower orders of the bodies given in Table II. This seems to force the 

 conclusion that the planetoids and smaller satellites were not formed 

 in a purely gaseous way. As this is a rather radical conclusion 

 it is well to note that the premises have not been strained to reach 

 this result but quite the opposite. The bodies have been taken at 

 their full present masses, whereas only their nuclei were really 

 involved during the critical genetic stages. The molecules are 

 taken in their present complex state, whereas in their volatile state 

 they were quite possibly simpler and hence more active. The 

 attractive power at the surface of the present cold concentrated 

 bodies was used, whereas the attractions at the surface of the 

 expanded gaseous bodies would be much lower. Other concessions 

 to conservatism were made. 



But this only excludes a direct or immediate formation by the 

 gaseous method. It leaves open the question whether or not the 

 cloud of precipitates into which the original mixed gaseous sub- 

 stances naturally passed could have completed the work. If so, 

 the genesis might have lain in the alien line of gaseous descent, 

 though not in that of strict gaseous formation. 



It was noted earlier in the discussion that the gases of the stony 

 and metallic substances must have begun to be precipitated soon 

 after expulsion from the sun. In the small detached segments the 

 precipitation must probably have gone on rather rapidly to com- 



'I am under obligations to Dr. Fred. E. Wright, of the Geophysical Laboratory 

 of the Carnegie Institution of Washington, for information and advice on points 

 involved here, as also to Professor W. D. Harkins, of the University of Chicago. In 

 the statements made I have endeavored to avoid all um ertain ground and leave 

 everywhere a margin of safety. 



