History of Astronomy for tfie Year l%p3. 1 7 



them as formed in the atmosphere ; others as coming from 

 the moon in two days and a half: some ascribe them la 

 volcanic eruptions, the focus of which is unknown j and 

 others to small planets, the revolutions of which have by 

 some obstacle been suspended. 



After that which appeared June 17, 1798, several stones, 

 one of which weighed twenty-six pounds, were picked up 

 at Villefranche, near Lyons *. Hitherto there have been 

 nine instances of such stones falling from the heavens : they 

 are all of the same nature, and, have no resemblance to any 

 of those known on the earth in mines or near volcanoes. 

 As for my part, when I consider that these stones are fria- 

 ble ; have an odour of sulphur ; that the explosion is heard 

 to the distance of thirty miles round ; and that the rolling 

 noise resembles that of musketry ; it appears to me that all 

 these circumstances, collected by M. Biot in his learned re- 

 port, which has been printed, indicate their formation in the 

 fire-ball, which is heard to detonate. Chemists are divided 

 in regard to the possibility of this formation ; but M. Cadet 

 Gassicourt, son of our celebrated chemist, who has already 

 distinguished himself in the same career, and who has pub- 

 lished an excellent dictionary of chemistry, reasoned with 

 me in this manner: 



U Hydrogen gas dissolves sulphur, charcoal, phosphorus, 

 zinc, and iron : its gravity is not thereby sensibly increased, 

 and it may rise thus charged to a considerable height. " 



May not hydrosulphurets which assume the gaseous state, 

 and which dissolve a great deal of earth and metals and vo- 

 latile acids, carry with them silex and magnesia, or the ele- 

 ments of the latter, which is strongly suspected to be a 

 compound body ? There is nothing in the received theories 

 which opposes this idea. IF the constituent principles then 

 of atmospheric stones can be at the same time in solution 

 in very light gases, when the hydrogen gas inflames they 

 will be formed into stones ; for the gas, by detonating, aban- 

 dons the bodies it held in solution ; the vacuum which it 

 forms draws towards the centre the moleculse of the revived 

 substances ; they yield to the general attraction, and tend to 

 unite : as they pass from the fluid to the solid state, they 

 necessarily disengage enough of caloric to produce incan- 

 descence, and that vitrification which we see at their sur- 

 face, but not enough to fuse them or oxidate them entirely. 

 Yesterday t the Institute received from the minister Chaptai 

 a stone of seven pounds weight, which fell on the 8th of 



* Journal de Physique, Germinal, an ft. f Novenbcr *1. 1803. 



Mo. 73. June 1804, B October 



