1882.] -^^1 [Chase. 



development and extension of "'the remarkable perception of great chemi- 

 cal truths which is apparent in the queries appended to the third book of 

 Newton's Optics, as well as in his hypothesis touching Light and Color." 

 Brodie's first announcement of the assumed existence of certain ideal ele- 

 ments was read before the Royal Society, May 3, 1806, and in the Spring 

 of 1867 Hunt "spent several days in Paris with the late Henri Sainte- 

 Claire Deville, repeating with him some of his remarkable experiments in 

 cliemical dissociation, the theory of which [they] then discussed in its re- 

 lations to Faye's solar hypothesis." I first invited attention to the "na- 

 scent" cosmical equation, or the equation which marks the limiting ve- 

 locity between tendencies to cosmical aggregation and to cosmical dissocia- 



qt 

 tion « = ^, on Dec. 18, 1863 {Proc. Am. Phil. Soc, ix, 284 7). On April 1, 



1864 {lb., p. 357), I said : "Absolute rest is apparently an impossible cop- 

 dition of matter, for, to whatever extent the action of opposing forces may 

 be relatively neutralized, the inconceivable rapidity of isthereal, planetary 

 and stellar motions produces a constant change of place. * * * 

 The sum of all the instantaneous energies is the same, whether the parti- 

 cle fall freely for any given time, or remain apparently at rest. All the 

 potential energy which is transformed in one case into the actual energy 

 of motion, in the other is counteracted by an equivalent and opposite actual 

 energy of elasticity. " On July 15, 1864 {lb. p. 408), I suggested "that 

 one of the most probable results of the rotation of the Earth with its atmos- 

 phere, in an aethereal medium, would be the production of two systems of 

 oscillations, moving with the rapidity of light." In October and Decem- 

 ber, 1864, I presented to the American Philosophical Society the "Numeri- 

 cal relations of gravity and magnetism," for which the Society awarded 

 its Magellanic gold medal, as furnishing "good reason to hope that by the 

 application of mechanical laws to the several phases of the ajthereal undu- 

 lations which produce the phenomena of light, heat, electricity, polarity, 

 aggregation and diffusion, we may obtain a clearer understanding, not 

 only of all the meteorological changes, but also of seismic tremors, crys- 

 tallization, stratification, chemical action, and general morphology," {lb., 

 p. 439). On Sept. 21, 1866 {Op. cit, x. 269), I gave my first indication of 

 the photodynamic importance of Earth's situation at the centre of the belt 

 of greatest condensation, and on April 2, 1869 {lb., xi. 106-7), I showed 

 that Sun's nascent or dissociative velocity is the velocity of light. 



201. Nitrogen and the Perissads. 



If Newton's belief that the inter-stellar aether is an expanded, universal 

 atmosphere, is true, it seems likely that the two principal constituent gases 

 of our own atmosphere may be everywhere as abundant, relatively, as thej' 

 are within the reach of our immediate observation. Even if this is not the 

 case, we may reasonably look for some special mathematical evidences of 

 the importance of two gases which have so wide a local diffusion, and 

 which have so large a sway in chemical combination and in organic 



