311 



ADDITIONS TO THE LIBRARY BY PURCHASE. 



Scientific Memoirs, selected from the Transactions of Foreign Acade- 

 mies of Science, Learned Societies, &c. Edited by Richard Tay- 

 lor, F.L.S. &c. Vol. IV. Part XVI. December, 1846. 8vo. 



The Edinburgh New Philosophical Journal. Conducted by Professor 

 Jameson. Vol. XLII. No. 83. January, 1847. 8vo. 



The London, Edinburgh, and Dublin Philosophical Magazine, and 

 Journal of Science. Third Series. No. 198. January, 1847. 

 8vo. 



Astronomische Nachrichten. Nos. 579, 584, and 585. 4to. 



Prof. Tucker read an " Essay upon Cause and Effect, being 

 an Examination of Mr. Hume's Doctrine that we can perceive 

 no necessary connexion between them," which was referred 

 to a Committee, consisting of Right Rev. Bishop Potter, Dr. 

 Demme and Dr. Bethune. 



Dr. Patterson again called the attention of the Society to the 

 circumstance mentioned at the last meeting, viz. that Mr. Sears 

 C. Walker had, on the 2d of February, detected a missing star 

 in the Histoire Celeste Frangaise, observed by Lalande on the 

 10th of May, 1795, which was near the path of Leverrier at 

 that date, and which may possibly have been that planet. 



Shortly after the arrival of the news of the physical discovery 

 of the planet, on a suggestion by Mr. Herrick, of its possible identity 

 with the Wartman planet of 1831, Mr. Walker engaged in the study 

 of the orbit of the former, and soon concluded that it could not have 

 been Leverrier, nor could any set of elements, with a mean dis- 

 tance at all probable, be found, that would represent the four places of 

 Wartman's planet, as published in the Comptes Rendus for 1836. 



In his first inquiry, he learned the probable near approach of the 

 orbit of Leverrier to the circular form. The analogy of the remote 

 planets with great masses led to the same conclusion. 



Jupiter's eccentricity is 0.048 

 Saturn's „ 0.056 



Herschell's „ 0.047 



Leverrier's „ <0.060 conjectured. 



If such were the character of the orbit, the radius vector, at so 

 great a distance, would vary but little with the time, and in a first 

 approximation might be wholly neglected. From the planets' places 



