1820.] the RedSnotcofthe Environs of Mount St. Bernard. 419 



over the snow, may very well colour it. A league from our hos- 

 pital, at the summit of the Col Ferret, there is a mine of specular 

 mao-netic iron ore (fer speculaire aimante) ; it may be recogmzed 

 in spring by the snow which is strongly tinged with red. 



I am, Sec. BisELx. 



St. Bernard, March 6, 1S19. 



P. S. As soon as red snow can be had, I will filter some, and 

 send you the residue ; but I shall not find any before the middle 

 of June. 



Anali/sis of ttoo Samples of Red Snoiv of St. Bernard. By M. 

 Peschier, Jlember of the Physical and Natural History 

 Society at Geneva. Extracted from a Memoir on the Subject, 

 read to the Society. 



I am not acquainted with any chemical inquiry into the cause 

 of the colour of the red snov/ of the Alps, except that made by 

 our illustrious countryman in 1778, and which is related in the 

 third volume of his Travels. The results of this inquiry are 

 confined to showing, that the residue of the red snow had an 

 earthy appearance, that when laid on burning coals, it emitted a 

 smoke, smelling like burnt grass ; that it furnished a dark-brown 

 solution, with muriatic acid, by the aid of heat, and a tincture 

 of a beautiful gold-yellow with alcohol, which left, as the residue 

 of its distillation, an oily substance, of a yellow-brown, having, 

 while burning, the smell of wax, and that the loss in v/eight of 

 the residue in this operation was rro-ths, which had made him at 

 first consider it as a dust of stamina, and that microscopical 

 observations had left him in doubt. As 1 was not acquainted 

 with any thing else on the subject, 1 have always wished to see 

 the attention of chemists directed to this interesting pheno- 

 menon. 



Two favourable opportunities having offered, I have thought it 

 my duty to take advantage of them ; and the following are the 

 essential parts of my inquny : 



My first operations were upon two residues of red snow, col- 

 lected with great care by the Prior of Great St. Bernard. One 

 of these residues, marked No. I. had an earthy appearance, and a 

 ferruginous, dirty-yellow colour. No. II. had the character of a 

 coarse vegetable earth, in which the naked eye could distinguish 

 fragments of lichen and of moss. It came from a small spot of 

 red snow, above which there was a reddish tinge, supposed 

 by the Prior to be produced by a cryptogamous plant, which 

 assumes this colour as it putrefies. This cause, he says, in the 

 note which accompanies these residues, rarely occurs, and does 

 not offer large coloured surfaces. No. I. when strongly heated, 

 lost 0" 10 of its weight, and assumed a darker colour. No. II. 

 emitted a pretty considerable smoke smelling hke burnt gi-ass ; 

 lost 0'40, and left a brilliant residue, of a violet colour. 



2 D 2 



