A NEW THEORY OF THE SUN. 233 



induction-coil. I then exposed the end of the tube projecting out of 

 the freezing mixture, backed by white paper, to solar radiation (on a 

 clear summer's day) for several hours, when, upon again connecting up 

 to the inductorium, a discharge, apparently that of a hydrogen vacu- 

 um, was obtained. This experiment being repeated furnished unmis- 

 takable evidence, I thought, that aqueous vapor had been dissociated 

 by exposure to solar radiation. The carbonic-acid tubes gave, how- 

 ever, less unmistakable effects. Not satisfied with these qualitative 

 results, I made arrangements to collect the permanent gases so pro- 

 duced by means of a Sprengel pump, but was prevented by lack of 

 time from pursuing the inquiry, which I propose, however, to resume 

 shortly, being of opinion that, independently of my present specula- 

 tion, the experiments may prove useful in extending our knowledge 

 regarding the laws of dissociation. 



It should be here observed that, according to Professor Stokes, the 



-ultra-violet rays are in large measure absorbed in passing through 

 clear glass, and it follows from this discovery that only a small portion 

 of the chemical rays found their way through the tubes to accomplish 

 the work of dissociation. This circumstance being adverse to the ex- 

 periment only serves to increase the value of the effect observed, while 

 it appears to furnish additional proof of the fact, first enunciated by 



-Professor Draper, and corroborated by my own experiments on plants, 

 that the dissociating power of light is not confined to the ultra-violet 

 rays, but depends in the process of vegetation chiefly upon the yellow 

 and red rays. 



Assuming, for my present purpose, that dissociation of aqueous 

 vapor was really effected in the experiment just described, and assum- 

 ing, further, that stellar space is filled with aqueous and other vapor of 

 a density not exceeding the ^ part of our atmosphere, it seems rea- 

 sonable to suppose that its dissociation would be effected by solar radia- 

 tion, and that solar energy would thus be utilized. The conjoint pres- 

 ence of aqueous vapor, carbonic acid, and nitrogen would only serve 

 to facilitate their decomposition, in consequence of the simultaneous 

 formation of hydrocarbons and nitrogenous compounds by combination 

 of the nascent hydrogen and the nitrogen with carbon in a manner 

 analogous to what occurs in vegetation. It is not necessary to sup- 

 pose that all. the energy radiated from the sun into space should be 

 intercepted, inasmuch as even a partial return of heat in the manner 

 described would serve to supplement solar radiation, the balance being 

 made up by absolute loss. To this loss of energy would have to be 

 added that consumed in sustaining the circulating current, which how- 

 ever, need not relatively be more than what is known to be lost on our 

 earth through the tidal action, and may be supposed to be compensated 

 as regards the time of solar rotation by gradual shrinkage. 



By means of the fan-like action resulting from the rotation of the 

 sun, the vapors dissociated in space to-day would be drawn toward the 



