1864.] 3g5 [Wilcocks. 



subject, we should endeavor to lay aside notions of matter already 

 acquired, and try to view it as we believe it to exist in the celestial 

 spaces. 



The physical constitution of the sun, as received by the best au- 

 thorities, I have described as far as I believe it to influence the mo- 

 tion of the ether. The rotation of that orb upon its axis, with the 

 position of the latter with reference to the ecliptic, I have recounted ; 

 also the observations of Secchi upon the relative heat of different 

 parts of the sun's surface, and the influence of this difference of 

 heat in determining the character of the ethereal currents. 



After duly considering the effect of these agencies upon each 

 other, the conclusions are reached that the ether in the solar system is 

 in constant motion, that it performs a circulation from the sun's 

 poles to the equator, and thence into the region of the planets, and 

 finally returning to the sun's poles, descends thereon in the form of 

 vortices; that the shape of the mass, as it advances into space, is 

 that of a huge plate, or more precisely a hollow cone, whose apex 

 forms a highly obtuse angle at the sun's centre. 



The existence of reflecting matter in the ether is shown from the 

 corona of light seen round the moon during a total eclipse of the 

 sun. 



It is suggested that a perspective view of the ascending current 

 of ether, as it advances through the region of the planets, produces 

 the appearance known as the zodiacal light. 



The weak points of former explanations of this phenomenon are 

 exposed, and the claim urged that the theory of ethereal currents, 

 derived altogether from independent data, affords the best explana- 

 tion. 



All the positive information we have upon the subject of ether is 

 derived from its effect upon comets, but long before Encke's day. 

 Sir Isaac Newton had undertaken to explain some of the most pro- 

 minent features of these bodies, upon the hypothesis of their moving 

 through a material fluid. 



The views of Newton, with respect to the position of the tails of 

 comets, I have noticed, with the reflection, that neither in his own 

 day nor ours have his ideas upon the subject received that support 

 from astronomers to which their merit entitles them. I have sug- 

 gested several reasons to account for the fact. 



The ingenious and plausible hypothesis of M. Valz respecting the 

 density of the ether in the solar system, is described, with his expla- 



VOL. IX. — 2z 



