1866.] On the Antiquity of the Volcanos of Auvergne. 205 
that they were ejected since the country had acquired its present 
configuration in all its important features. 
Subsequent observations have, indeed, shown that no sharp line 
of demarcation exists between the two, as there are instances of 
volcanic rocks which, although they have descended the slope of a 
valley, were themselves scooped out to a great depth by the same 
agency. But that the distinction can be clearly traced in many 
instances cannot, I think, be disputed by any who have visited the 
locality. 
Moreover, a great difference exists between the two classes in 
their external characters, the former possessing in general the com- 
pactness and stony aspect belonging to trap and prophyry, the 
latter that cellular, glassy appearance and harsh feel which charac- 
terize modern lavas. 
The former accordingly support a luxuriant vegetation, whilst 
the latter are scarcely decomposed by time, and therefore afford but 
little pasturage, and that generally of the worst description. The 
former, too, constitute extensive sheets of rock spreading over large 
districts, and cannot be traced to any point of issue, whereas the 
latter may generally be found to emanate from a crater, from which 
they proceed into the lowest ground contiguous, in a stream, the 
breadth of which bears no proportion to its length. 
In accordance, then, with the views prevalent at the time I first 
visited the country, the former class would be entitled to the name 
of ante-diluvial, and the latter to that of post-diluvial, the one 
being regarded as produced before the great catastrophe by which 
the valleys of the country were then conceived to have been excavated, 
the latter subsequently to that event. 
It therefore became a question of some interest to determine 
whether any records existed which should indicate the continuance 
of the activity of the Auvergne volcanos down to the period of 
authentic history. But on this point classical authorities are silent. 
Julius Cesar, by no means inattentive to the external features of 
the countries he invaded, makes no allusion to any volcanic pheno- 
menon having arrested his nctice, although he encamped upon the 
plains of Auvergne, and laid siege to Gergovia, the principal city in 
the district. 
His silence, however, it may be said, only proves that during 
the period at which he was engaged in that part of Gaul the 
igneous forces were slumbering, as might have happened in the case 
of Etna or Vesuvius during any such short interval of time. 
But what shall we say of the omission of Pliny to include 
Auyergne amongst the regions in which he records the existence of 
fiery mountains ; and what of the silence of Strabo on the same 
point? to say nothing of the poets, who indulge in such frequent 
mention of Etna and Lipari, but make no allusion to volcanos in 
other portions of the then known globe. 
