234 



vestigation, which in these latter times has 

 much engaged the attention of mineralogists. 

 Does the Archipelago of the Canary islands con- 

 tain any rocks of primitive or secondary forma- 

 tion ; or is there any production observed, that 

 has not been modified by fire ? This interesting 

 problem has been examined by the naturalists 

 with Lord Macartney, and by those who accom- 

 panied Captain Baudin in his voyage to the 

 Austral lands. The opinions of these distin- 

 guished scientific men are in direct opposition 

 to each other ; and a contradiction of this na- 

 ture is so much the more striking, as there is no 

 question here of one of those geological reveries, 

 which we are accustomed to call systems, but of 

 a positive fact, easy to verify. 



Doctor Gillan, according to the narrative of Sir 

 George Staunton # , imagined, that he observed, 

 between Laguna and the port of Orotava, in very 

 deep ravines, beds of primitive rocks. This as- 

 sertion, though repeated by a number of travel- 

 lers, who copy each other, is not the less inaccu- 

 rate. What Dr. Gillan calls somewhat vaguely, 

 mountains of hard ferruginous clay, are nothing 

 but an alluvion, which we find at the foot of 

 every volcano. Strata of clay accompany ba- 

 salts, as tufas the modern lavas. Neither Mr. 

 Cordier nor myself observed in any part of Te- 

 ller iffe a primitive rock, either in it's natural place, 



* Voy. de Lord Macartney, t. i. p. 15. 



