238 KINETIC THEORIES OF GRAVITATION. 



theory of temperature, expansion, conduction, evaporation, and the 

 transformation and conservation of energy ; and although three years 

 later than Herapath's remarkable announcement of the theory of gaseous 

 temperature, is doubtless an independent and original discovery ; for 

 such it is entitled to be called. There is now little question that while 

 the molecular excursions in gases take place in straight lines or in hy- 

 perbolic trajectories, the atomic motions within the molecule (whose 

 marvelous regularity of periodicity is attested by the fixed refrangibili- 

 ties of the spectrum) are really described in elliptic orbits, as Seguin 

 had so early preconceived. 



The writer proceeds to apply this hypothesis to a variety of appar- 

 ently unconnected phenomena, as to the sudden development of motion 

 in the fracture of a " Prince Rupert's Drop" or unannealed glass tear; 

 to the action of the steam-engine, in which a large amount of molecular 

 orbital motion in the vaporized water is transformed into. the rectilinear 

 or trauslatory motion of the piston ; for " if, as we suppose, an angular 

 motion has been changed into a rectilineal motion or into a motion of trans 

 latiou, we should find after the effect only the quantity of motion which 

 has not been employed in producing the useful effect." He shows that 

 the same theory explains satisfactorily the great degree of refrigeration- 

 observed in the higher regions of our atmosphere, while by the material 

 theory of caloric the upper regions should be the hottest ; and he main- 

 tains that even " the motion produced by organized bodies may be ex- 

 plained in the same manner as the steam-engine." This is certainly a 

 very remarkable prevision of the correlation between the physical and 

 the organic forces. 



Jt was not till 1848 that Seguin commenced a series of memoirs, read 

 before the French Academy of Sciences, on the nature of the molecu- 

 lar forces, but dealing mainly with cohesion regarded as a phase of 

 gravitative action. A theory of mutual impacts and reactions between 

 the molecules of matter and the atoms of the aether was proposed but 

 not very clearly presented.* With a communication, made October 22, 

 1849, the author submitted the results of experiments showing actions 

 " very analogous, if not identical in their effects, with that of gravita- 

 tion." The apparatus exhibited consisted essentially of a magnet at- 

 tached to a pendulum which produced motion in small iron bullets sus- 

 pended a short distance therefrom. 



In an editorial resume of Seguin's work on "Molecular Physics," in 

 Abbe Moiguo*s Cosmos, in 1852, the Abbe, after alluding to Newton's 

 speculations, affirms with characteristic confidence and earnestness : 

 " If there is anything certain in the world, it is that the molecules of 

 bodies and bodies themselves are not really self-attractive; it is that 

 attraction is not an intrinsic but only a developed force ; it is that not- 



" Comptes Rendua, September 25, 1848, vol. xxvii, pp. 314-318; January 22, 1849, vol. 

 xxviii, pp. 97-101; October 22, 1849, vol. xxix, pp. 425-430; January 19, 1852, vol. 

 xxxiv, pp. 85-89 ; November 7, 1853, vol. xxxvit, pp. 703-703. 



