TttANSACTIONS OP TIlE SECTIONS. 



51 



change by continuous degrees, as Newton andBoscovich suppose, and 

 which breaks the continuity in the law of force. 



The second principle is, the author thinks, as simple and as natural as 

 can well be conceived, and an evident result from phsenomena and the 

 first principle. 



It was stated In a treatise lately published by the author, that nature 

 presents two classes of atoms, the one comprehending ponderable matter, 

 such as oxygen, carbon, &c., which adhering with great tenacity may be 

 called tenacious atoms (till a better name be found). The other consists 

 of atoms which manifest their existence by motions and actions under a 

 form which has been called aethereal ; hence they may be denominated 

 sethereal atoms ; they comprehended the electric fluid, caloric, and light. 



In the same work the atoms of the electric fluid were considered as 

 having a much greater absolute force than those of caloric and light. 

 This has been confirmed by subsequent observations, entitling the elec- 

 tric atoms to the rank of an intermediate class, so that we may distin- 

 guish atoms into three classes, tenacious, electric, and aethereal, not dif- 

 fering in nature but only by a marked difference in their absolute 

 force. Of the 1st and 3rd classes there are many sorts, but of the 

 electric fluid probably only one sort. 



The weights of the other atoms used in this paper are taken from 

 Dr. Thompson's determinations. Respecting carbon, whose weight, 

 according to Dr. Thompson, is 12 (taking oxygen 16), and according 

 to Berzelius It is 12^, the specific gravities are calculated on both sup- 

 positions, and then compared with those found by experiment in the 

 following table : 



E 2 



