MHOI OT -nq sampan ai/- 



UNDULATORY SYSTEM RESTS ON CONTRACTION. 69 



lo i 



And as it is clear, that under all circumstances, such as have 

 been described, as well from reflecting surfaces as from terres- 

 trial bodies by combustion, producing light, the system of 

 emanation is decidedly requisite to perfect the production of 

 radiant light ; and further, that the united forces described 

 under the laws of undulation and emanation appear essential 

 to explain the imputed velocity of light in its passage through 

 space (as before observed), by substituting the period required 

 for the union of the spherical compound atoms of light, for the 

 less rational conception that one single atom of light could by 

 any projected force be carried through atmospheres of great 

 and various densities, at the enormous rate of 192,000 miles 

 in a second. 



The foundation of the undulatory system may rest on the 

 appearances afforded by the contraction of the compound 

 spherical atom of light, from the expanded state in which it is 

 exhibited, in No. 5, Plate IV., and which contraction) although 

 described to be occasioned by the needful condensation of the 

 molecules of hydrogen and nitrogen to the highest density, 

 that of the oxygen molecule, by which, on calculation, the area 

 is reduced, say from 400 to 212.5, or nearly one half although 

 that reduction has been by accident omitted to be comparatively 

 depicted as it should have been in the diagram, No. 6, Plate 

 IV. : yet it is requested that the circumstance may be carried 

 in recollection, in the future consideration of the condition of 

 condensation to which the compound atoms of light are re- 

 duced, when brought by the pressure of emanation to the state 

 of linear rays. 



those of the rays of celestial light projected from that effulgent atmosphere; 

 and may not such circumstance have an influence in producing the black 

 lines of shade which striate the spectrum of the triangular prism, and form a 

 ring, accompanying the blue ray, as exhibited by the convex lenticular prism 

 of Field ? 



