PREFACE. 
vn 
properly worked out, would be found to contain the same succession 
of palaeozoic deposits as had been described in the Silurian region of 
England and Wales. From that moment Mr. Murchison resolved to 
visit Russia, and fairly to test, whether the British palaeozoic classifica- 
tion would be found equally true over a vast area, in which, since few 
or no igneous rocks were known, the history of succession might, he 
hoped, be read off in a very perfect and unbroken manner. Having in 
the meantime unravelled the structure of the Rhenish provinces, in 
company with his friends Professor Sedgwick and M. de Verneuil, he 
invited the latter (whose acquaintance with the specific distinctions of 
the ancient mollusca is so well known) to join him in a geological 
survey of Russia. 
To invade Russia, however, as unassisted geologists, with mere ham- 
mers and compasses, would have proved but a fruitless mission, had not 
the countenance of the Imperial Government been obtained. This was 
secured through the very friendly intervention of Baron de Brunnow, 
His Impel ial Majesty s representative at the Court of London, who, 
exhibiting a generous feeling for the advancement of science, strongly 
recommended the undertaking to the protection of his Sovereign. 
Arriving in the Neva in the early summer of 1840, Mr. Murchison and 
M. de Verneuil were previously assured of profiting by the aid of their 
friend Baron A. von Meyendorf, who having been appointed to conduct 
an inquiry into the state of manufactures and trade of the internal 
governments, had begged them to unite with him, and had further 
obtained the cooperation of two able naturalists, the Count A. von Key- 
serling and Professor Blasius ; thus hoping that his tour might atford 
many interesting results besides those immediately connected with its 
object. With these associates, the first researches were commenced in 
the environs of St. Petersburgh, and on the banks of the rivers Volkof 
and Siass ; and they were followed by others on the banks of the Lake 
Onega and the environs of Petrozavodsk. Notwithstanding, however, 
the zeal and assistance of Baron A. von Meyendorf, it was not possible 
b 2 
