1858.] MURCHTSON — -NORTHERN HIGHLANDS, ETC. 355 



spoken of. In spite of torrents of rain, we had, however, observed 

 that some of the sandstones and coarse grits of the West Coast were 

 associated with such crystalline rock ; but, unable to follow up the 

 observation, we laboured under the erroneous conviction, in com- 

 mon with all our contemporaries, that the great mountainous masses 

 of red conglomerate and sandstone of the West Coast were simply- 

 detached portions of the Old Red Sandstone of the East Coast, as 

 they had been represented to be by all preceding authors. Nor 

 was this inference to be wondered at ; for at that time both Prof. 

 Sedgwick and myself were entirely unacquainted with the true 

 succession of the Lower Palaeozoic Rocks below the Old Red Sand- 

 stone. This opinion respecting the age of the conglomerates of the 

 West Coast remained, indeed, so fixed in the minds of all succeeding 

 geologists, including Hugh Miller, that even in my own work, 

 ' Siluria,' published in 1854, these North- Western conglomerates 

 and sandstones, which I had not then revisited, were considered to 

 be of the same age as those of the true Old Red on the East Coast 

 of Scotland, In fact, notwithstanding the very able researches of 

 Cunningham, in addition to those of Macculloch and Hugh Miller, 

 no one had obtained a correct notion of the general order of those 

 older rocks of the N.W. Highlands. 



Just at that period (1854), my friend Mr. Charles Peach, already 

 distinguished by discovering those fossil remains in the hard quartz- 

 rocks of the maritime headlands of Cornwall* which enabled me to 

 assign them to the Lower Silurian age, being sent from his Custom- 

 House station at Wick to visit a wrecked ship on the north coast of 

 Sutherland, discovered certain organic remains in the limestone of 

 Durness, which, though imperfect, were unquestionably shells. 



Now, as I had previously expressed the opinion that large por- 

 tions of the so-called primary or crystalline rocks of the Highlands 

 of Scotland would prove to be equivalents of Lower Silurian de- 

 posits in the south of Scotland f, I naturally felt anxious to revisit 

 the spot where the important discovery had been made. Having 

 requested Professor Nicol to accompany mc, the results, as related to 

 my own views, were given at the Glasgow Meeting of the British 

 Association in 1855. Having procured some additional fossils (one 

 of them a chambered shell), I then still more held to the opinion, 

 that the quartz-rocks and their subordinate limestones w^re of 

 Lower Silurian age. I also seized that opportunity of maintaining 

 the dignity of the Old Red Sandstone of the N.E. of Scotland as 

 a great geological series, and asserted my opinion, that it is the true 

 and full equivalent of the Devonian group of other countries. 



Still two essential points remained to be distinctly cleared up. 

 Professor Nicol and myself had noted the infraposition of a red con- 

 glomerate and sandstone to the quartz -rock and limestone ; but, 

 foiled by heavy rains and mist, we could not follow out the line of 

 junction, and ascertain the persistence of such order in the adjacent 



* Trans. R. Geol. Soc. Cornwall, 1849, p. 103 ; and Quart. Journ. Geol. Soc. 

 vol. viii. pp. 5, 13. 



t Quart, Journ. Geol. Soc. vol. vii. p. 169. 



