J. W. JUDD ON THE SECONDARY ROCKS OP SCOTLAND, 663 



II. History oe Previous Opinion on the Subject. 



For the earliest notices of the very interesting rocks which it is 

 the object of the present memoir to describe, we must go back more 

 than a century to the famous work of Pennant, who mentions the 

 occurrence of compressed Ammonites in the rocks of Duntulm in 

 the north of Skye*. At a little later date the Liassic sandstones of 

 the southern coast of Mull are referred to by Mr. Abraham Mills in 

 letters which were read before the Eoyal Society in the year 

 1790 f. 



In Jameson's ' Mineralogy of the Scottish Isles/ published in the 

 year 1800, there are a number of very interesting observations on 

 the Secondary rocks of Mull, Eigg, and Skye, the remarkable rela- 

 tions of which to the volcanic masses of the area were by no means 

 overlooked, though they were too frequently misinterpreted. 



Several foreign geologists who have been attracted to the Western 

 Isles of Scotland by the grandeur and interest of the volcanic phe- 

 nomena displayed in them, have given in their works many valuable 

 notes concerning the associated Secondary strata of the district. 

 Among these we may especially mention M. Faujas de Saint-Fond^, 

 M. Ami Boue§, M. L. A. Necker-de-Saussure ||, and MM. Yon 

 Oeynhausen and Yon Dechen ^[, each of whom has contributed some 

 useful observations on the strata in question. 



The geologist who has, however, done far more than any other 

 in seeking for and investigating the relations of the isolated patches 

 of Secondary strata in the Western Isles of Scotland is Dr. John 

 Macculloch. During many years he was indefatigable in his exer- 

 tions to explore those interesting regions, which imperfect means of 

 communication, with stormy seas and a most trying climate, had 

 combined to render a terra incognita to the geologist. The first 

 series of the Transactions of our Society contains several papers 

 bearing striking witness to the earnestness and enthusiasm with 

 which he prosecuted his self-imposed task ; and the great work in 

 which he finally embodied the results of his observations ** will always 

 remain no less a landmark of the progress of geological knowledge 

 than a monument of the zeal and ability of its author. 



As my own task has led me to follow very closely in the footsteps 

 of Macculloch, I think that it is incumbent upon me to speak a word 

 in defence of the fair fame of one to whose previous researches I 

 have been on so many occasions very deeply indebted. In a former 

 volume of this Journal, not only have Macculloch's labours been 



* Pennant's ' Tour in Scotland and the Hebrides in 1772,' p. 304. Published 

 in 1774. t Phil. Trans, vol. lxxx. pt. 1, p. 85 (1790). 



\ Voyage en Angleterre, en Ecosse et aux iles Hebrides. Paris, 1797. See 

 also his ' Essai de Greologie/ Paris, 1809. 



§ Essai geologjque sur l'Ecosse. Paris. 



|| Voyage en Ecosse et aux iles Hebrides. Geneva, 1821. 



% Karsten's Archiv, vol. i. 1829. 



** A Description of the Western Islands of Scotland, including the Isle of 

 Man. London, 1819. Two volumes with Atlas. 



