OBSERVATIONS ON THE ELECTRIC RESONANCE (BOURDONNEMENT) 



OF MOUNTAINS.* 



Bv M. Henri de Saussurk. 



[ Translated for the Smithsonian Institution. ] 



Leaving Saint-Mointz (Grisons) June 22, 1865, I made an ascension of the 

 Piz Surlcy, a mountain composed of crystalline rocks, whose summit, moro or 

 less conic, attains an altitude of 3,200 meters. 



During' the previous days the north wind had constantly prevailed ; on the 

 22d the wind became variable, and the sky was charged with floating clouds. 

 Towards midday these vapors augmented and gathered in masses above the 

 highest summits, sustaining themselves, however, at such an elevation as not to 

 veil most of the spires and peaks of the Engadine, on which fell soon some local 

 showers. Their aspect of powdery vapors, semi-transparent, caused us to take 

 them for mere squalls of snow or sleet. 



In effect, towards one in the afternoon, we were ourselves assailed by a fine 

 and thin sleet, at the same time that similar squalls enveloped most of the spires of 

 rock, such as the Piz Ot, Piz Julier, Piz Langard, &c., and the snowy sunmiits 

 of the Bernina, while a voilent fall of rain descended on the valley of Haint- 

 Moritz. 



The cold increased, and half an hour later, when we had arrived at the top of 

 the Piz Surlcy, the fall of sleet becoming more abundant, we disposed ourselves 

 to take a repast, and leaned our staves against a small pyramid of dry stones 

 which crowns the summit of the mountain. Almost at the same instant I expe- 

 rienced in the back, at the left shoulder, a piercing pain, like that whicli would 

 be produced by a pin slowly driven into, the flesh, and when I applied the hand 

 to the place without finding anything there, similar pain was felt in the 

 right shoulder. Supposing that my linen overcoat contained pins, I threw it 

 off; but, far from liniling relief, I perceived that the pains augmented, invading 

 the whole back from shoulder to shoulder; they were accompanied by tickling, 

 by distressing twinges, such as W'ould be produced by a wasp which was creep- 

 ing over the skin and piercing me with stings. Hastily removing my second 

 coat, I discovered nc>thing of a nature to wound the llesli. The pain, which 

 still continued, then assumed the cliaracter of a burn. Without reflecting, I 

 imagined that my woolen shirt, though I could not tell how, had taken fire, and 

 I was going to throw ofl" the rest of my apparel, when our attenti(m was attracted 

 by a noise which resembled the humming of large insects. This prociH-'dcMl from 

 our three staves, which, inclined against the rock, were cluinting loudly, giving 

 out a whistling sound analogous to that ot a kettle, the water of which is on tho 

 point of entering into ebullition. All thi« may have occupied four or live niinutea. 



1 comprehended, on the instant, that my ])ainful sensatii)ns proceeded from an 

 intense electrical efllux which was taking place from the summit of the mountain. 

 Some extemporized experiments on our staves yielded no appearance of any 

 spark nor any light appreciable by day ; they vibrated with force in the hand 



* The observations wliich follow had been communicated by correspondence to M. J. 

 Fournet, who has introduced them in his notices on Electric Rri^ions, published in the 

 Comptts Rcndus dc l\icad(mic dr.s Sciences, tome xliv, lS(i7. Wo give thcai hero with some 

 modifications and considered in a niuru special point of view. 



