W. A. Norton— Physical Constitution of the Sun. 403 



cesses of change in operation on its surface, we are at least 

 entitled to assume the following as probable hypotheses. 



1. That the sun exercises a repulsive action upon the mole- 

 cules of every gas or vapor that subsists at its surface, or is at 

 Miv time in any part of the region of space exterior to the sur- 

 i'aiv : that this force is the sum of all the heat impulses propa- 

 i:;U(.d in ethereal waves from all the gaseous molecules posited 

 alxne tlie solid or liquid body of the sun, and from the surface 

 iiioleciiles of this central mass, except in so far as these impul- 

 : intercepted in their passage ; and that it is opposed 

 3 of gravitation, which is due to a virtual attraction 



■ force of gravitation, i 

 •' r ii' sun's entire mass, — so that the effective force soliciting 

 - iM'ous molecule is the difference between these two 

 ttractive and repulsive, by which it is urged. 

 lat the force of solar repulsion, since it consists of im- 

 I'lvjpagated in ethereal waves, is comparatively more 

 ■ in proportion as the atomic weight of the solar vapor 

 It being assumed that the quantity of matter in any 

 - proportional to its volume. 



It in a hypothetical condition of equihbrium of the 

 tiuosphere the elastic force of each of its vaporous con- 

 >ntuents, at any depth, will consist in the intensity of the effec- 

 ^ye heat impulses tending to urge its molecules outward ; which 

 ^W be counteracted by the weight of the superincumbent 

 portion of the atmosphere. Now, let us assume, for the moment, 

 that at some anterior epoch in the sun's history, all the Present 

 vaporous constituents of the sun's atmosphere were diffused 

 throughout a space exterior to the central body of the sun and 

 hraited by the spherical surface (A), at which the molecules of 

 tte vapor of greatest atomic weight are in equilibrium, under 

 tbe action of their own weio-ht and of the heat-repulsion urging 

 them upward. This h ypothetical state of things could not con- 

 tinue, since the atoms of each of the other solar vapors would 

 t>e urged upward by an effective force. If we conceive a small 

 quantity of each of them to escape from all points of tnis sur- 

 face, the rising vapors will ascend to greater lieigits nM^^^'P* " 

 ^on as their atomic weights are less, and tinally ^vhen me 

 ^mlibrium is attai-ned, form a series of sphencnlenv opt , 

 ^^^0% detached from each other, and arranged in the '^" * ' "^^ 

 atomic weights ;—beo-inmpo- with the heavier nietaliic xa[ u> 

 ^d terminating with the lighter (potassium, ^^^y""; ^^^ \; !^^ 

 '^^ permanent ^.x<e^rs,\\h livdro-en outermost. If "thu >mall 

 portions of each of the vapors were to rise fr^m t^ie surti. A^ 

 7y would serve to augment the thickness of the ^n^ kn^es 

 ^!«^ady formed : and the same would be true for e^cli suedes 

 >ve discharge. The iinal result would be the same if the di^ 

 charge were continuous <lurin^ a cei-tain interval of tmie, as 



