of the Volcano of Peuquehes. 317 



Mendoza, on the eastern side of the Andes, and even as far east- 

 ward, as the province of San Luis. 



I have been unable to obtain any evidence of its having been in 

 a recent state of activity prior to that event ; but since then its 

 eruptions have been very frequent, and have attracted the notice 

 of the inhabitants both of Mendoza and Chile. These eruptions 

 have principally consisted of immense quantities of volcanic ashes 

 or pumice, thrown up in a state of such minute division, and of so 

 little specific gravity, as to be carried by the wind to immense dis- 

 tances. These volcanic products, however, generally fall in the 

 greatest abundance on the mountains and vaUies in the neighbour- 

 hood, more especially to the eastward. In the valley of the Tenu- 

 yan such occurrences have been frequently witnessed by those in- 

 dividuals who pass part of the year there in attendance on their 

 cattle, and likewise by the miners, who live during the whole year 

 near the summit of the lofty mountain of San Pedro Nolasco, in 

 Chile, situated about 30 miles S.W. by W. of the volcano. On 

 my visiting these mines in 1826, I was informed by the princi- 

 pal miner, in charge of the silver mines, who had been resident 

 there during a number of years, that he had seen many of these 

 eruptions since the occurrence of the earthquake already men- 

 tioned, and more especially during the preceding year : that 

 thev generally commenced with a loud murmuring noise, followed 

 by an explosion, and the eruption of volcanic matter, forming at 

 first a dense cloud over the volcano, and then gradually subsiding, 

 and disappearing in the direction in which the wind might blow 

 at the time, which was almost always eastwards ; and he likewise 

 remembered, that although the ashes rarely fell upon any part 

 of the mountain of San Pedro Nolasco, yet the nature of the erupt- 

 ed matter was rendered sufficiently apparent by the gray or ash- 

 coloured tint which it gave to the snow on the tops of the moun- 

 tains in its vicinity, during some time after the occurrence of an 

 eruption. 



During my residence in the city of Mendoza, distant upwards 

 of 90 miles to the N.E. of the volcano, I had only once an oppor- 

 tunity of personally witnessing the fall of one of these showers of 

 volcanic ashes at so great a distance from the place where it had been 

 ejected. This event took place on the 15th December 1824, at 

 5 p. M. ; the day was fine, with a cloudless sky, and a moderate 

 breeze coming from the south-west. For some time before the fall 

 of ashes took place, a dark insulated cloud had been observed in the 

 sky in the direction of Peuquenes, but had altogether disappeared 

 on its occurrence. I succeeded in collecting a small portion of the 

 ashes from the flat roof of a house, and on examination found it to 

 consist of minute particles, of a grayish colour, of small specific gra- 

 vity, and in appearance not unlike common pumice-stone reduced 

 to powder. On inquiry, I was informed that on various occasions 

 showers of ashes, of a similar description, had fallen at Mendoza. 

 And on the 22d July 1827, one took place, which fell under the ob- 



