ELECTRIC EESONANCE OF MOUNTAINS. 347 



bottom of tlio abyss. But scarcely lind I renclied half way when the storm, 

 bursting forth with astonishing suddenness, obliged nie to reasceud as soon as 

 possible towards the })oint I had left. 



There was at first a fine rain, then small hail, driven by a violent wind. In 

 a moment the mountain became white and the cold intense. The bursts of 

 thunder, at first inteiTupted, soon seemed to roll without cessation and with fearful 

 ci'ashes, especially when they issued from the circuit of the crater, into which 

 darted, at J'requeut intervals, flashes of lightning. Without shelter in the midst 

 of these naked rocks, without even a block ))ehind which to cower, nothing 

 remained for us but to sit down on the earth with backs turned to the hail. After 

 the lapse of some time the cold became insupportable, and the dread with which 

 the tempest had inspired us drove us from the summit, though our observations 

 were untinished. While we descended rapidly the rocks of the Nevado, rain 

 for an instant succeeded the hail, and as we coasted a small stony ravine,* formed 

 by ancient outcrops of trachyte, and where the vegetation of shrubs commences, 

 the storm seemed mon:ientarily to subside. The thunder ceased or drew off to a 

 distance, but we presently saw a grayish cloud advance, which enveloped us 

 during its passage, and ivas accompanied tcith slcct. Immediately the hair of our 

 Indian attendants was oljserved to be in agitation as if about to stand erect, and 

 we experienced various electrical sensations in the beard and ears. Next a dull, 

 undeiinable noise was heard, at first feeble though general, but presently stronger 

 and perfectly distinct. There was a universal crepitation, as though the small 

 stones of the whole mountain were clashing against one another. Our terrified 

 Indians gave free vent to their superstition in words, and it cannot bo denied 

 that there was something disquieting in the sounds which then prevailed in the 

 mountain. This phenomenon lasted five or six minutes, and then the rain and 

 thunder again commenced in full force. The storm became more suppt)rtable 

 when we had descended to the upper limit of the forests, although one of those 

 diluvial rains was falling which characterize the hot season imder the tropics. 



M. F. Craveri, an Italian physicist, settled at Mexico, who, before myself, had 

 made au ascent of the Nevado de Toluca at the commencement of the rainy 

 8eas(m, recounted to me that he had been a witness of the same facts, which he 

 could not recall without an impression of terror. The electric state was still 

 more violent. The traveler in question ascended the mountain May 19, 1S4£>, 

 by the southeast side, starting fioni Tenango, and descended by the northwest 

 blope to Toluca. The southwest side was at that season destitute of snow. The 

 electric phenomenon was sudderdy brought on by a cloud arriving from the west, 

 and which had perhaps taken its rise on the fields of snow of that side. Scarcely 

 were the travelert* enveloped in it when they experienced the sensation which 

 electricity produces, and this was almost immediately fullowed by a dtdl noise. 

 They felt irregular currents of electricity at all their extremities, the fingers, the 

 ears, the nose. The fear which seized th(;m in the midst of these lofty solitudes 

 imj)elled them at once to commence their descent at a precipitate })acc. The 

 tjiunder did not yet resound, but at the end of five minutes there fell a snow 

 resembling rice, and the cloud communicating its electricity to the ground, the same 

 noise arose therefrom which I have indicated above. This noise was very intense 

 and seemed general in all the mountain. The long hair of the Indians became 

 stiff and erect, giving to their heads an enormous magnitude. 'V\\(i sight of this 

 phenomenon added to the j)anic terrors of the excursionists, who had counted iqjou 

 finding nothing but pleasure in the adventure. 



The very singular noise which makes itself hoard in the rocks of the mountains 

 at the moment of the electric phenomenon deserves to be studied l)y competent 

 l)hysicists. It resenil)les the rattling sound which pebbles would })roduco if 



* For greater precision I iiavo mc^ilied this passaf^o, biiving written in my tormer notice: 

 "lis we followed a stony valley." There -was, in iiict, but a slight depiessiou of the soil, 

 vrheucc the word " valley " says too much and might bo misuuderstood. 



