466 Proceedings of Philosophical Societies, [Dec, 



ralizing agents. In conclusion, Dr. Davy observed, that as the 

 substance from which these crystalline compounds had been 

 produced could not be imagined to have been in solution, their 

 formation must be referred to an intimate motion of its particles, 

 effected by the conjoint agency of chemical affinities, electro- 

 chemical attraction, and the attraction of aggregation. He 

 suggested the application of this inference to explain various 

 phaenomena in mineralogy and geology. 



Observations on the apparent Positions and Distances of 468 

 Double and Triple Fixed Stars, made at the Observatory at 

 Pasy, near Paris, during the Summer of 1825. By James South, 

 Esq. FRS. 



Nov. 24. — At this meeting a paper was read On the Compa- 

 rison and Adjustment of the New Standards of Weights and 

 Measures. By Capt. H. Kater, FRS. 



LINNEAN SOCIETY. 



JVbv. 1 and 15. — At these meetings a paper was read, enti- 

 tled, '* Observations on the unimpregnated Vegetable Ovulura, 

 and on the Nature of the Female Flower in Coniferae and Cyca- 

 deae." By Robert Brown, Esq. FRS. FLS. &c. 



ASTRONOMICAL SOCIETY. 



Nov, 11. — ^The Society resumed its sittings this evening: 

 and the President took the opportunity of calling the attention 

 of the members to the remarkable circumstance of the appear- 

 ance of no less than four comets during the recess : an occur- 

 rence unparalleled in the history of astronomy. The Jirst of 

 these (he observed) was discovered by M. Gambart, at Mar- 

 seilles, on May 19, in the head of Cassiopea. The second by 

 M. Valz, at Nismes, on July 13, near % Tauri. The third by 

 M. Pons, at Florence, on Aug. 9, in Auriga. The fourth 

 (which was the most interesting and important of the whole, 

 Bince it had been the object of solicitude at every observatory, 

 and was anxiously expected and looked after by every astro- 

 nomer) was discovered about July or August last. The 

 President remarked this last comet (which is better known 

 by the name of the comet of Encke) has now made 13 revo- 

 lutions within the last 40 years : six of which have been regu- 

 larly observed by astronomers. It was first seen in 1786; 

 afterwards in 1795, 1805, 1819, 1822, and in the present year. 

 It makes a complete revolution in about 1207 days, or about 3^ 

 years. 



A paper was read, on the latitude of the Royal Observatory 

 of Greenwich, by the Astronomer Royal. The co-latitude of 

 this observatory, as computed from Dr. Bradley's observations 

 tinder the direction of Dr. Maskelyne, is 38° 3K 22'',0 ; a de- 

 termination which is subject to the sum or the difference 

 of two separate errors, one, in determining the zenith distance 



