- 0. 8. Hastings— Constitution of the Sun. 41 
. The molecular weight is probably not great, for, though 
precipitated below the upper natural limit of its vapor, there 
are few elements found in abundance above it, and those in 
general of low vapor density. 
3d. The element is not a rare one. Of these guides the last 
is of the least value. 
and the analogous but less common element boron may add a 
minor effect, 
In the explanations which I shall give of the remaining 
phenomena, it may serve to fix the ideas, to think of the gran- 
ules which characterize the sun’s photosphere as clouds of a 
substance like precipitated silicon. At any rate we are sure 
