380 Royal Astronomical Society. 



Lychnis alpina. 

 This elegant little plant was first discovered by the late Mr. Don 

 in the summer of 1795 ; and again accidentally met with in consider- 

 able abundance by Sir John Ogilvie, Bart, in August last. The 

 specimens from Clova agree in every respect with those in the Lin- 

 naean Herbarium. The capsule in this plant is uniformly five-celled, 

 but the thin partitions in the advanced state are found occasionally 

 partially obliterated. 



Mulgedium alpinum. Sonchus alpinus ofLinnceus. 



The late Mr. Don was acquainted with several stations for this 

 plant ; and Dr. Graham's party found it in five different places, some 

 of them being seven or eight miles apart. One or two of the sta- 

 tions are fortunately quite inaccessible, so that the plant is not likely 

 to be entirely eradicated. 



It is singular that of this, which is also a Lapland plant, there is 

 no specimen in the Linnaean Herbarium; the two so named are North 

 American species, and apparently from the Upsal garden ; one of 

 them being Sonchus Jloridan us, and the other example (which has 

 also the number of the Species Pluntarum attached to it,) Sonchus 

 spicatus of Lamarck, the LeucophcBus of Willdenow. Both these are 

 also species of Mulgedium ; and our late excellent President, misled 

 by the number attached to the specimen in the Linnaean Herbarium, 

 has been induced to publish this last as the real alpinus, substitu- 

 ting for the actual plant the name ofcceruleus. All these plants more 

 naturally associate with Lactuca than with Sonchus, only differing 

 from the former in the less attenuated apex of the achenia. 



royal astronomical society. 



Dec. 14, 1832. — The following communications were read: — 



I. Extract of a letter from Professor Santini to Professor Airy, 

 dated Nov. 23, 1832. Communicated by Professor Airy. 



M. Santini succeeded in making several observations of Biela's 

 comet, which are given in the monthly notices of the Society. 



On his own observations and those of Sir J. Herschel, M. Santini 

 observes : — 



"It is remarkable that its place should have been found nearly 

 intermediate between my ephemeris and that of M. Damoiseau ; 

 from which it seems to follow, that the line of perihelion passage 

 was badly determined in both, which is probably owing to the as- 

 sumption of a constant orbit through the whole period, in the cal- 

 culation of the co-ordinates for the computation of the perturba- 

 tions ; and as, in May of last year, the comet approached very near 

 to Jupiter, a slight error in these co-ordinates may have had a 

 sensible influence on the perturbation of mean motion, on which 

 depends the return to perihelion. 



" I looked carefully for Biela's comet on several evenings in 

 September, with the equatorial of this observatory, but I could not 

 discover any thing that had the least resemblance to a comet. The 



