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Coupe de Jaujac,” has been erupted through the coal measure 
rocks, and has a large and perfect crater covered now with 
chestnut trees, but within which grow several good plants, such 
as Dianthus ccesius , Cephalanthera rubra , and Convolvulus 
cantabricus . iSilene saxifraga grows on rocks in the bed of 
the Alignon. 
The village of Jaujac stands upon the lava torrent which 
came down from the crater, dammed up the river Alignon, 
and for a time formed a lake above. We were there on a 
Sunday; and the people were all dressed in their best, the 
women at mass, and the men smoking and playing dominoes in 
the inns. The vineyards on the slopes of the hills between 
Jaujac and Thueys were clustered with grapes, which were 
being gathered, and a well-dressed woman presented me with 
as many as I could bring away. Here we met a priest, who 
addressed us on the geology of the district, and who knew 
Mr. Scrope and M. Elie de Beaumont apparently better than he 
did the geology of his own country. The walls of columnar 
basalt at Jaujac are very striking, and are seen in contact with 
the old land surface over which the lava flowed. Very different, 
too, is the quality of the land since the overflow by the basalt. 
The decomposition of the lava plateau forms a rich generous soil 
on which grow the mulberry and the fig. The granite is sterile 
enough, and requires constant aid from manures. Walking 
for some distance down the river, we could see that the thickness 
of the basalt could not be less than 1 00 feet, and we observed 
that, in passing over bosses of granitic rock the lava had crystal- 
lized in prisms at right angles to the inclination of the surface 
over which the lava flowed. In this splendid river section 
three points of geological interest are clearly to be seen. First 
the river Alignon flowed in a channel between granitic and Car- 
boniferous rocks as deeply as it does at present ; then came the 
outbursts from the Coupe de Jaujac, which filled the old river 
bed with lava and dammed the river; then the river flowed 
over the basaltic plateau, and since that has cut its way down 
through 100 feet of solid lava to its present level. On the left 
bank of the river below the bridge there is a corner below the 
hill before ascending the pathway to Thueys which looks like 
a young “ chimney,” for the basalt is partially dislocated, and 
there is a little outburst of volcanic sand. Below the village of 
Nerac prismatic columns of lava may be seen resting on the 
rolled pebbles of the old river bed. 
We went to Antraigues for the Coupe d’Eyzac, distant about 
five miles from Vais. The road follows the course of the 
Volane river through a romantic gorge, which leads up to the 
granite mountains of the Haute Vivarais. This valley differs 
from the others, inasmuch as the basalts appear to have been 
