Prof. P. E. Chase on the Nebular Hypothesis. 449 



between resisting points, those points tend naturally to nodal, 

 and from internodal positions. In order to maintain unifor- 

 mity in the wave- velocity, the setherial molecules must be 

 uniform, not only in volume, but also in aggregate inertia. As 

 the inertia of the resisting points increases, the inertia due to 

 internal astherial motions should therefore diminish, and vice 

 versa. In other words, the uniform elementary volume may 

 be represented by the product of atomic weight by specific 

 heat; and the laws of Boyle (or Mariotte), Charles, and Avo- 

 gadro follow as simple and necessary corollaries. 



In order that uniform undulations should produce motion, 

 there must be at least two points of resistance. Those points 

 would approach each other until the interior undulating resist- 

 ance equalled the exterior undulatory pressures, when their 

 motion would be converted into rotation or into orbital revo- 

 lution. Their common centre of revolution might become the 

 centre of a new elementary volume, thus giving rise to the 

 various laws of combination by volume, combination without 

 condensation, condensation of two volumes into one, three 

 volumes into two, or four volumes into two, as well as to 

 general artiad and perissad quanti valence. 



When perifocal collisions change parabolic or elliptic into 

 circular orbits, there should be increasing density towards the 

 principal centre of the system. Further collisions and con- 

 densations would produce tendencies to both nucleal and atmo- 

 spheric* aggregations, and consequent binary groupings. 

 These laws are exemplified in the solar system by the general 

 division into an intra-asteroidal and an extra-asteroidal belt, 

 and by the subdivision of each belt into two pairs, — the inner 

 belt being denser than the outer, and the inner member of each 

 pair being denser than its companion — Mercury being denser 

 than Venus, Earth than Mars, Jupiter than Saturn, Uranus 

 than Neptune. This arrangement towards the Sun as a prin- 

 cipal centre appears, however, to be of more recent date than 

 the tendency to condensation in the Telluric belt ; for Earth 

 is denser than Venus, and the great secular ellipticities of Mars 

 and Mercury suggest the likelihood of a quasi-cometary origin. 

 Similar tendencies would contribute to the chemical grouping 

 of atoms by pairs, which is essential for polarity and for the 

 already enumerated laws of chemical combination. 



In the " nascent state " particles may be regarded either as 

 parabolically perifocal, with the velocity of complete dissocia- 

 tion from a given centre, or as relatively at rest, and ready to 

 obey the slightest impulses of central force, The mean vis 

 viva of a system formed by two such particles would be 

 mx ( N /2) 2 + mx0 = 2??ix 1, 

 * Proc. Soc. Phil. Amer. xiv. p. 622 scqq. 



Phil Mag. S. 5. Vol. 6. No. 39. Dec. 1878. 2 G 



