246 



Comptes Rendus Hebdomadaires des Seances de I'Acadeaiie des 

 Sciences, 1839. 1'^'" Semestre. Nos. 3, 4 By the Academy. 



The folJowing communications were read : — 



1. Notice of some observations made during the Storm of Ja- 

 nuary 1839. By John Scott Russell, Esq. 



The author stated, that the paper consisted principally of com- 

 munications made by members of this society, which had been 

 placed in his hands. Many points in the statistics of the storm had 

 been noticed with great accuracy ; and it is important, in the pre- 

 sent promising condition of our knowledge of the statistics and phi- 

 losophy of this branch of meteorology, that such communications 

 should be arranged and preserved, for the purpose of furnishing 

 materials for its improvement. The author went on to explain the 

 views of the nature of storms which had been successively pro- 

 pounded by Franklin, Espy, Redfield, and Reid. He then read 

 various communications of observ'ations, from Sir John Robison, 

 Professor Christison, Mr Nichol^ Mr Stevenson, Professor AValiace, 

 Mr Hunter of Thurston, Mr Scott, Sir David Brewster, Mr Rus- 

 sell, Mr Bald, and other gentlemen, who had, with himself, taken 

 an interest in the subject. The p.iper concluded with deductions 

 of a general nature from the facts observed. 



»^ 



2. On Fresnel's Law for the Intensity of Reflected and Re- 

 fracted Light. By Professor Kelland^ 



The object of this memoir was to remove from the molecular 

 theory, diiBculties in which the recent investigations of Mr Green 

 appear to involve it. The question at issue is the ratio of the den- 

 sities of the ether within and without a refracting medium. The 

 usual mechanical hypotheses would appear to lead to the conclusion 

 that the former density is the greater ; whilst from the molecular 

 hypothesis the latter appears to be the truth. 



In the memoir of Mr Green appears a very strong argument for 

 the hypothesis as originally stated by M. Fresnel, together with a 

 statement which adds force to the objection, otherwise strong, 

 against the molecular theory, viz. that vibrations are not necessa- 

 rily transversal. It will be found in this memoir, that all the con- 

 clusions, and all the statements, of Mr Green, excepting only those 

 which translate into language his resulting equations, are perfectly 

 compatible with the molecular hypothesis, and may be deduced 



