HYPOTHESIS OF NEWTON. 5 



But if the aether be the cause of solution, and of 

 the elastic force of the atmosphere, it is mani- 

 festly identical with caloric. It is true that in 

 the fifth query, towards the close of the Optics, 

 Newton represents heat as consisting in a vibra- 

 tory motion among the particles of bodies, and 

 that the whole theory of the Principia was founded 

 on the hypothesis that space is a vacuum ; which 

 is certainly at variance with the foregoing views 

 of the aether. It is also inconsistent with his 

 doctrine of light, which he regarded as a material 

 substance, perpetually flowing from the sun and 

 fixed stars through space. But that caloric does 

 not consist in mere motion or vibration among 

 the particles of ponderable matter, would appear 

 from the following considerations: 



1. That it may be added to and subtracted 

 from other bodies, and measured with mathe- 

 matical precision, as all good thermometers de- 

 monstrate : 



2. That it augments the volume of bodies, which 

 are again reduced in size by its abstraction : 



But if Newton had traced the word sether to its primitive roots, 

 he would have found that it was a Greek noun, which was 

 derived from two Phoenician or Hebrew words, Ath or Aith the 

 sun, and Ur fire, meaning the solar fire, a discovery which 

 probably would have modified all his physical investigations, 

 and have given a totally new aspect to the whole circle of the 

 Sciences. The truth is, that a complete Etymological Dictionary 

 would sweep away innumerable misconceptions, errors, and me- 

 taphysical subtleties, which have gradually arisen from the re- 

 volutions in language, and the adoption of words, the primitive 

 meaning of which has not been understood. 



