630 



to be identical with the phlogiston of former chemists. He cites 

 the opinions of Priestley, Cavendish and Watt, as corroborating his 

 views, and interprets their experiments in conformity with the hypo- 

 thesis he has adopted. 



" Suggestion intended to confirm Franklin's Theory of Electro- 

 statics, by explaining the phenomena of Repulsion between bodies 

 negatively electric." By James A. Smith, Esq. Communicated by 

 S. Hunter Christie, Esq., Sec. R.S., &c. 



The author conceives that in negatively electrified bodies, or 

 bodies having less than their natural quantity of electricity, the re- 

 dundant matter must have a tendency to escape, and thus the equi- 

 librium of its cohesion is destroyed ; and that two bodies in such a 

 condition must mutually repel each other. 



*' On Sir Isaac Newton's Method of finding the Limits of the 

 Roots of Equations." By Herbert Panmure Ribton, Esq. Com- 

 municated by John George Children, Esq., F.R.S. 



The author states that he has reason to believe that by general- 

 izing from successive inductions of equations, a formula more uni- 

 versal than Newton's Binomial could be found. 



" Description of a Method of Registering Magnetic Variations." 

 By Charles Brooke, Esq., M.B. Communicated by G. B. Airy, 

 Esq., F.R.S. 



A vertical stream of light issuing through a slit in the copper 

 tube of a camphine lamp, is reflected by a concave mirror fixed ver- 

 tically on the axis of a suspended magnet, and condensed into a 

 focus by a cylindrical lens placed at the distance of about seven 

 feet from the mirror. The luminous image, which shifts its position 

 according to the movements of the magnet, but to a much greater 

 extent, impinges on highly sensitive photographic paper, wound 

 round a horizontal cylinder, which is made, by a watch movement, 

 to revolve once in twelve hours. Thus, by a combination of the 

 vertical movement of the paper with the horizontal movement of the 

 image, the magnetic curve of variation is distinctly portrayed and 

 registered. 



