GEOLOGICAL OBSERVATIONS IN FRANCE. £9l7 



Virons of Priay; wlience the road to Lyons is over plains Road to Lyons* 

 covered with pebbles,, frequently in such quantity as to pre- 

 vent the bind from b,eing cultivated. The prevailing species 

 are quartz, and hard quartzose gritstone. The pebbles of 

 the Alps indeed frequently occur, as micaceous s hist, schis- 

 l^se Korn.blende, and serpentines: yet when We traverse the 

 bed of any torrent or river coming from the adjacent moun- 

 tains, the calcareous stones always predominate. 



Between lake Sylant and Ghatillon, about two or three 

 miles from this town, on the left bank of the little river is 

 a tolerably fine spring, called Entrebilliet, the temperature Heat of 

 of which on the 1st of April was 7*5° of Deluc [49° F.], ''P'-^'^S^' 

 while that of the open air was 6-5° [467^]. The height of 

 the place above the sea, as found by the barometer, was 241 

 toises. At Varambon, near Pont-ci'Ain, a spring rose out 

 of the ground, the temperature of which was 9° [5ii*25°], 

 and that of . the open air 12° [59°]- The height of this agreeing with 

 place was about 1 40 toises. These two observations agree ^^"^^^'^^''*^^' 

 sufficiently with the law established empirically by Mr. 

 Saussure, that the heat of the air decreases about l°of Deluc 

 for every hundred toises in height. 



From Ghatillon to Nantua we found a prodigious quan- Box. - 

 tity of box. All the country, except the summits of the ' 



mountains, which are crowned with firs, is covered with 

 this shrub ; and from the warmth of its local aspect, it 

 grows to a considerable size, as in Campania and the East. 



From the environs of the loss of the Rhone we do not Vines, 

 meet with any vines in the road, till we reach Cerdon*. At 

 this place is a plantation, reaching from the top of the moun- 

 tain, which is 403 feet higher than the lake of Geneva, to 

 the bottom of the declivity on the high road, which is 192 

 feet lower than the lake. 



if in proceeding from Lyons into Auvergne we travel di- 

 rectly westward, traversing the Lyonnois and Forez, we are 

 constantly on the primitive soil. The chief base of the Granitic coun* 

 countiy of Limagnej that fine part of France, is well known ^' 



•- The extent to which Mr. Arthur Young has availed himself of his 

 accurate ob.servations on the locality of certain cultivated plants, among 

 which is the vine, is well known. 1 do not hesitate to pursue his views 

 of vegetable physics, when opportunity offers, 



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