2 PROFESSOR FORBES ON THE VOLCANIC GEOLOGY OF THE VIVARAIS. 
usual thoroughfare of the Rhone, down which travellers and tourists glide by 
thousands, without spending a thought upon the intricate country which lies on 
their right, their attention being rather attracted to the more striking features of 
the outlying portions of the Alpine chain on the left, where the noble outlines of 
the mountains of Dauphiné hold out a more tempting prospect of romantic 
scenery and of geological interest. 
Nevertheless, from a very early period of the revival of geological studies in 
these latter times, the Provinces of the Ardéche and Haute Loire (the ancient 
Vivarais and Velay) attracted considerable notice. When men were no longer 
content to ascribe, with VoLraire, the presence of extraneous fossils in mountain 
rocks to the passage of pilgrims with their scallop shells,—or with others, the 
scorize of ancient volcanoes, covering an area of many square miles, to the iron 
forges of the Romans,—they began, very properly, to compare the marks of the 
most apparently recent changes of the earth’s surface, not however belonging to 
the historic period, with those going on under our own eyes, such as the eruptions 
of volcanoes, and by clearly establishing identity of effects in some cases, were led 
to almost irresistible conclusions from analogy in others. Thus the presence of 
volcanic craters, scorize, and lava currents, in several parts of central France, 
could not be doubted by any one who had seen the burnt ground of Etna or 
Vesuvius. The phenomena should rather be called identical than analogous ; 
but the argument of analogy from the lavas thus detected, to the volcanic origin 
of lava-like stone or basalt in many countries where no red scorize, no declivitous 
streams of once melted matter, and no indubitable craters could be found, opened 
up a field for more prolonged study, and more cautious generalization. In this 
department Fausas DE St Fonp, a native of the Vivarais, distinguished himself ; 
and with great industry, and considerable, though not invariable judgment, he 
set about identifying the features of the unquestionable lava streams of his own 
country with more obscure, because more ancient ejections of melted matter 
forming rocks on the surface, not only there, but in distant countries, particularly 
in Great Britain, whither he made a journey on purpose. To establish indubitably 
the connection of basalts with lavas was the main object of his large work 
in folio, on the Extinct Volcanoes of the Vivarais and Velay, published in 1778,* 
which contains observations of merit, and descriptions generally exact, notwith- 
standing the rudeness of the engravings by which they are illustrated. This work 
contains, perhaps, the most complete description of the volcanic district of the 
department of the Ardéche which has yet been published, and the ample nar- 
rative of Fausas has been the guide of every subsequent explorer (and they have 
not been numerous) of this remarkable country. The circumstance of proximity 
of situation, which led Fausas to explore the hills of his own neighbourhood (for 
* Recherches sur les Volcans eteints du Vivarais et du Velay, avec un discours sur les volcans 
brilans, &e. Grenoble et Paris, 1778. 
