338 NORTHERN CHILE. [CHAP. xvi. 



pressure of the atmosphere over a wide extent of country, might 

 well determine the precise day on which the earth, already stretched 

 to the utmost by the subterranean forces, should yield, crack, and 

 consequently tremble. It is, however, doubtful how far this idea 

 will explain the circumstance of torrents of rain falling in the dry 

 season during several days, after an earthquake unaccompanied 

 by an eruption ; such cases seem to bespeak some more intimate 

 connexion between the atmospheric and subterranean regions. 



Finding little of interest in this part of the ravine, we retraced 

 our steps to the house of Don Benito, where I stayed two days 

 collecting fossil shells and wood. Great prostrate silicified trunks 

 of trees, embedded in a conglomerate, were extraordinarily nume- 

 rous. I measured one, which was fifteen feet in circumference: 

 how surprising it is that every atom of the woody matter in this 

 great cylinder should have been removed and replaced by silex so 

 perfectly, that each vessel and pore is preserved! These trees 

 nourished at about the period of our lower chalk; they all be- 

 longed to the fir-tribe. It was amusing to hear the inhabitants 

 discussing the nature of the fossil shells which I collected, almost 

 in the same terms as were used a century ago in Europe, namely, 

 whether or not they had been thus " born by nature." My geo- 

 logical examination of the country generally created a good deal 

 of surprise amongst the Chilenos : it was long before they could 

 be convinced that I was not hunting for mines. This was some- 

 times troublesome : I found the most ready way of explaining my 

 employment, was to ask them how it was that they themselves 

 were not curious concerning earthquakes and volcanos? why 

 some springs were hot and others cold ? why there were moun- 

 tains in Chile, and not a hill in La Plata ? These bare questions 

 at once satisfied and silenced the greater number; some, however 

 (like a few in England who are a century behindhand), thought 

 that all such inquiries were useless and impious ; and that it was 

 quite sufficient that God had thus made the mountains. 



An order had recently been issued that all stray dogs should be 

 killed, and we saw many lying dead on the road. A great number 

 had lately gone mad, and several men had been bitten and had 

 died in consequence. On several occasions hydrophobia has pre- 

 vailed in this valley. It is remarkable thus to find so strange and 

 dreadful a disease, appearing time after time in the same isolated 

 gppt. It has been remarked that certain villages in England are 



