THE SUN. 59 



1. 



IHE SUN CONSIDERED AS THE CENTRAL BODY. 



The la7itern of the ivorld {lucer7ia Mundi), as Copernicua 

 names the Sun,^ enthroned in the center, is, according tc 

 Theon of Smyrna, the all- vivifying, pulsating heart of the 

 Universe ;t the primary source of light and of radiating heat, 

 and the generator of numerous terrestrial, electro-magnetic 

 processes, and, indeed, of the greater part of the organic vital 

 activity upon our planet, more especially that of the vegetable 

 kingdom. In considering the expression of solar force in its 

 widest generality, we find that it gives rise to alterations on 

 the surface of the Earth — partly by gravitative attraction — 

 as in the ebb and flow of the ocean (if we except the share 

 taken in the phenomenon by lunar attraction) — partly by light 

 and heat-generating transverse vibrations of ether, as in the 

 fructifying admixture of the aerial and aqueous envelopes of 

 our planet, from the contact of the atmosphere with the vap- 

 orizing fluid element in seas, lakes, and rivers. The solar 

 action operates, moreover, by diflerences of heat, in exciting 

 atmospheric and oceanic currents, the latter of which have 

 continued for thousands of years (though in an inconsiderable 

 degree) to accumulate or wash awaj'- alluvial strata, and thus 

 change the surface of the inundated land ; it operates in the 

 generation and maintenance of the electro-magnetic activity 

 of the Earth's crust, and that of the oxygen contained in the 

 atmosphere ; at one time calling forth calm and gentle forces 

 of chemical attraction, and variously determining organic life 

 in the endosmoee of cell-walls and in the tissue of muscular 

 and nervous fibres ; at another time evoking light-processes 

 in the atmosphere, such as the colored coruscations of the polar 

 light, the thunder and lightning, hurricanes, and water-spouts. 



Our object in endeavoring to compress in one picture the 



* I have already, :n an earlier part of this work (vol. ii., p. 308, and 

 note *), given the passage imitated from the Sornnhim Scipionis, in ch. 

 X. of the first book De Revolut. 



t "The Sun is the heart of the Universe." — Theonis Smymcei, Pla- 

 tonici Liber de Astronomia, ed. H. Martin, 1849, p. 182, 298: r?}f kutpv- 

 Xla^ [J-icsov TO irepl tov i'jTitov, olovel KapSiav ov^a tov TxavTog, bdev (pspov- 

 CIV avTov Kal ttjv tpvxvv dp^auivjjv dia izavTo^ rjaecv tov a6/uaT0C tetU' 

 uevrjv drro tuv Trepdruv. (This new edition is worthy of notice, since it 

 completes the peripatetic views of Adrastus, and many of the Platonie 

 dogmas of Dercy Hides.) 



