on comets. jgy 



terized, which must have belonged to the genus lagomys, 



of which there arc at present but three species known, all 



of them discovered in Siberia by Pallas. 



It would be a subject of some curiosity, to examine these ^ 



... „ , , , , ,. , Fartnar lnqui- 



breccia still farther on the spot, and obtain from them a rie. iespccting 



larger quantity of bones, in order to discover whether these them pointed 

 animals were buried there in gieat numbers; whether the 

 bones of other animals accompany them, and, if so, of 

 what countries these are natives; and lastly if their bones 

 are worn, broken, and have the appearance of having been 

 brought from a distance. 



You are aware, sir, without my entering into the subject, 

 bow much light the solution of all these questions would 

 throw on the history of the revolutions of our globe, at pre- 

 sent so obscure. 



VII. 



Extract of a Letter from Professor Picot of Geneva to the 

 Editors of the Bibliotheque Britannique*. 



JL Shall first speak of that beautiful comet, which excited 

 such a lively and general curiosity last year [1807]. Disco- i807. 

 vered in September, immediately after passing its peri- 

 helion in the constellation of the Serpent, it travelled the 

 following months nearly at the rate of a degree a day in 

 those of Hercules and the Lyre. Imperceptibly diminishing 

 in lustre as it increased its distance from us, and even ceas- 

 ing to be visible to the naked eye, it was followed only by a 

 few astronomers in those intervals, when the fogs and winds 

 permitted observations to be made. Mr. Olbers availed 

 himself of these favourable moments, and observed it till me 

 19th of February, when his labours were interrupted by 

 an illness, from which he was not recovered the 28th of 



* Journal de Physique, vol. LXVII, p. 153. 



O 3 April, 



