Rejicction and Refraction of Light. 145 



repulsion of the oxygen ; hence there would rest on the surface a stratum 

 of ethereal atoms, consisting of about two thousand millions. For the 

 same reason other strata would be superposed, forming on the whole an 

 atmospherule about the oxygen, and containing a number of ethereal atoms, 

 to the amount of some millions of millions.* 



11. Hence it follows, that to any large body, such as the earth, or a 

 planet, will be attached a dense and extensive atmosphere of ethereal 

 matter, reaching in altitude perhaps many hundred miles, more or less, 

 according to the proportionate quantity, and the mass of the body : also 

 the atoms of the body will be severally invested by atmospherules, and the 

 vacuities or pores will be occupied by the ethereal matter. Hence we see 

 how the gross or common atmosphere may arise as a natural consequence, 

 its nature, altitude, and density, being limited by the quantities and qualities 

 of the two classes of atoms present. It likewise follows, that the surfaces 

 of detached bodies will retain a mass of ethereal matter more dense than 

 in their interior, and still more so at the angular edges and corners. The 

 ethereal matter is admirably suited, and circumstanced, to be projected 

 with immense velocity during chemical combinations, especially when they 

 are energetic ; and, when moving with a certain velocity, to excite tiie 

 nerves of the eye at the seat of vision ; hence we conclude, that light is 

 these atoms moving witli a due velocity. See the New Theory of Physics, 

 and the Treatise on Physical Optics lately published, in which these sub- 

 jects are elucidated and applied. 



12. The reader will now be prepared to understand the doctrine of reflec- 

 tion and refraction, according to each of the three views, which may, after 

 these |»reliminaries, be brought into a moderate compass for easier compari- 

 son. Tlie facts to be explained are the following : — 



'• Wliile in the same medium, light moves in a straight line, at the rate 

 of about 200,000 miles in a second. 



* Let /, be the thickness of the atmospherule, r, the radius of the sphere of re- 

 pulsion, a, the distance between the centers of two ethereal atoms at the surface of 



[r-l-a]" — rii 

 the oxygen, and n the number of strata; then, t-=z > and, since a is very 



small in respect of r, wo shall have for an approximate value, t = na: in the above 



T 



example, a = , and if we take < = »•, we shall have n = 4000 \/ 10. and 



4000 \/ 10, ' 



the number of atoms in each stratum being 3.1416 X 640,000,000, we shall find, that 

 the atmospherule having a thickness, not more than the radius of the sphere of repul- 

 sion, will contain nearly twenty- five millions of millions of ethereal atoms. This 

 guppoRCR that the atoms rest directly on each other ; but this will not be the case, 

 since the center of a higher will rest over a point between three or more of the lower, 

 or not 80 high, as determined by the above rule; hence the above sum will be too 

 ■mall ; and if we suppose the atmospherule extended, and the force of the ethereal 

 atoms nnich less, the number in the atmospherule will be immensely increased, and 

 •till more, if we take account of the pressure of the superincumbent atoms. 



