ii Desmarest' s Interest in Basalt 53 



of the pillars, the vast size to which they reached, the 

 colossal cliffs along which they were ranged in admirable 

 regularity, had vividly aroused the curiosity of those who 

 concerned themselves with the nature and origin of 

 minerals and rocks. Desmarest had read all that he could 

 find about this mysterious stone. He cast longing eyes 

 towards the foreign countries where it was developed. 

 In particular, he pictured to himself the marvels of the 

 Giant's Causeway of the north of Ireland, as one of the 

 most remarkable natural monuments of the world, where 

 Nature had traced her operations with a bold hand, but 

 had left the explanation of them still concealed from mortal 

 ken. How fain would he have directed his steps to that 

 distant shore. Little did he dream that the solution of 

 the problems presented by basalt was not to be sought in 

 Ireland, but in the heart of his own country, and that it 

 was reserved for him to find. 



Before referring to the steps in Desmarest's progress 

 towards the discovery of the origin of basalt, let me briefly 

 sketch what was known on the subject at the time when he 

 began his researches. Agricola, who, as I have just said, 

 revived the Latin name Basaltes for this dark prismatic 

 rock, mentioned that it was to be seen in different parts of 

 Germany, and in particular that it formed the eminence on 

 which the old castle of Stolpen in Saxony had been built. 1 

 It was afterwards found to be abundantly distributed, not 

 only in Saxony, but in Silesia, in Cassel, and in the valley 

 of the Rhine above Cologne. 2 In these places it usually 



1 De Natura Fossilium, lib. vii. p. 315. Folio, Basel, 1546. 



2 Various authors who had noticed the occurrence of basalt before the 

 publication of his memoir are cited by Desmarest. M&m. Acad. Roy. 

 Sciences, vol. for 1774, p. 726 et seq. 



