56 Mr Scrope's Observations on 



forms an exception to this uniform character, and hence, Mr 

 Scrope was led to examine them with care, with the view of 

 referring them to the ordinary principles of volcanic action. 



In this examination, Mr Scrope has analyzed the opinions 

 of M. de Humboldt with that respect and courtesy which are 

 due to his distinguished talents, and he has never permitted 

 the spirit of controversy to disturb the serenity of philo- 

 sophical discussion. We should have wondered, indeed, how 

 any man could have approached even to the errors of that 

 great traveller with any other feelings but those of affec- 

 tion and respect, had we not perused a recent attempt 

 to blacken and insult his high reputation. Every philoso- 

 pher and naturalist in Europe view with indignation this 

 warfare against a man who has contributed so much to the 

 sciences which they cultivate ; and every Englishman must 

 feel that the character of our literature has been compromised 

 by such unmeasured abuse and depreciation of foreign talent. 



" Previous to 1759,'" says Mr Scrope, " it appears that 

 the plain, from which Jorullo now rises, presented traces of 

 former volcanization ; its soil being composed of tufa ; and 

 the neighbouring mountains consisting of trachyte and basalt. 

 In September of that year, a violent series of eruptions took 

 place, of which M. de Humboldt distinguishes the results in 

 the following order. 



1st, The production of six volcanic cones, composed of 

 scoriae and fragmentary lava. 



'idly, That of a promontory of basaltic lava proceeding 

 from the summit of the largest of these cones (Jorullo,) which 

 still emits wreaths of vapour from the interior of its crater. 



3dly, The elevation in a convex form of the plain, (four 

 square miles in superficial extent) upon which the cones were 

 thrown up, and the centre of which is occupied by the largest 

 (Jorullo,) at whose base the plain is higher by 550 feet than 

 without the limits of this space. The plain, which M. de 

 Humboldt calls " un errain bombe en forme de vessie," and 

 the convexity of which he attributes to inflation from belozv, 

 is represented as closely sprinkled with thousands of flattish 

 conical hillocks, from six to nine feet high, formed of basaltic 



