and near the inn called Venta de Belate, not far from the top of the mountain, being acceffible to animals, the following plants are to be feen, celandine, mint, cuckowflower, crowfoot, plantain, fowthistle, figwort, archangel, dock, arfmart, and two forts of maidenhair on the walls, from whence I judge that if a houfe was built on the highest and most barren mountain, and the ground manured with the dung of animals, we fhould foon perceive the fame plants that are obferved in the neighbourhood of villages and in plains, and that it is not a good rule to judge of the height of a mountain by the appearance of plants, if no diftinction is made between the fpontaneous ones and the others, elfe we might conclude that the little hill of Meudon near Paris is as high as the Pyrenees.

From the Venta de Belate it is an easy defcent into another vale well cultivated with vines and corn, which extends as far as the city of Pamplona, capital of the kingdom of Navarre. In this vale there is a wood of ftately oaks, with plenty of box, thorntree, wild roses and other common plants of cultivated countries. You keep conftantly on the borders of a rivulet running amongst round fandftone of a purple colour, fimilar to thofe on the other fide towards France. I faw the following plants in the plains of Pamplona, on the fide of the roads, in the fields and the vineyards; two forts of eringo, one called the hundred headed

A

fort,

fort, and the other with large leaves, poppy, dockweed, white horehound, vipergrafs, elder, white goofegrafs, devilfbit, cinquefoil, croffwort, henbane, tutfan, agrimony, teafel, hawthorn, reft harrow, crowfoot and bullace.

In this plain it is clearly feen how the limy rock decays, for in an almoft perpendicular fiffure above an hundred feet high, the earth which at firft fight and even to the touch appears to be clay, is nothing more than limy earth, mixed with a fmall portion of clay, the refult of rotten plants as I experienced with the acid I always carry with me when I travel. The fame fort of earth of a blueifh colour is found near Pamplona, but harder, and fo very hard in a hill oppofite to the city, as to deferve the name of ftone, difpofed in ftrata with the fame obliquity as the fiffure abovementioned, all which proves the decompofition of the rocks.

Leaving Pamplona, I traverfed a champaign country for two leagues and a half to the mountain opposite, which having paffed, a variety of cultivation takes place. Some limy rocks are fo barren, that nothing is to be feen but butchers broom, a few oaks, juniper, and lavender, for two leagues and a half further, when I arrived at the city of Tafalla; then paffing an extenfive plain full of aromatic plants, had five leagues to Capar

rofo.

1

rofo. This plain may be thrown into four divifions, the first from Tafalla being olive trees, the fecond vineyards, the third corn-fields, and the fourth barren, except a few olive trees and some corn-fields near Caparrofo, where a hill divides the plain, and now and then, the rounded purple ftone shews itself again the same as in France.

From Caparroso I croffed a high hill where any miner might mistake the ftrata of gypseous stone which is only one or two inches thick, for fpar, but you may dig as deep as you please, and never find any thing but gypfum, which is very seldom seen where there is mineral. The country is every where barren and miserable, a perfect defert without water, and nothing but rosemary, lavender, and a few starved oaks. After quitting this wretched district a fertile plain opens to the eye, supplied by wheels with water from the Ebro, and here I faw the tamarisk, which is a beautiful plant when in flower.

From Caparrofo it is four leagues to the Ebro in a plain bordered by a chain of hills from eaft to weft, composed of limy earth mixed with gypfeous stone, sometimes in ftrata, granulated, or in maffes, white as fnow. This chain extends about two leagues, and towards the middle, where it is the highest, stands the village of Valtierra: about half way up, there is a mine of foffil common falt,

which being transparent and resembling chryftal, goes by the name of Salgem, and is feen above ground where the fhaft is made at the entrance of the mine. About twenty paces within, one observes that the falt, which is white and abundant, has penetrated into the very beds of gypseous ftone. This mine may be about four hundred paces in length, with several lateral shafts, upwards of eighty paces, fupported by pillars of falt and gypfum, which the miners have very judiciously left at proper diftances, fo that it has all the appearance of a gothic cathedral. The falt follows the direction of the hill, inclining a little to the north, like the ftrata of gypfum, being comprised in a space about five feet in height without variation, and feems to have corroded several beds of gypsum, and marl, and infinuated itself into their place, though much of thofe fubftances ftill remain.

At the end of the principal fhaft, the miners have carried out a branch to the right, where the faline bed appears to have followed exactly the inclination of the hill, which in that part is very perpendicular: this ftratum of falt defcends to the valley, and goes on to the opposite hill; which regularity destroys the fyftem of those who pretend that fal gem is formed by the evaporation occafioned by fubterraneous fire. If this was the cafe, the beds would not be undulated in this manner, resembling

refembling those of coal at Chamond, near Lyons, in France, or those of afphaltos, in Alface, that follow the elevation and declivity of the hills or vallies, the bitumen often floating on the water when it meets with it. I am of opinion that falt grows in the mine like minerals, that coal is the product of foffil wood, as appears from fuch remnants as are found in the mines, § and that the afphaltos

*

Afphallos or Jewish bitumen is fo called from the lake Afphaltites or dead fea in Judea, which rifes up in the nature of a liquid pitch, and floats upon the furface of the water like other oleaginous bodies, and is condensed by degrees through the heat of the fun; the Jews formerly ufed it to embalm their dead. The Arabs gather it for pitching their ships, but the Europeans use it in medicinal compofitions, especially iu theriaca, or Venice treacle; also for a fine black varnish, in imitation of that of China. Rolt's dict. of commerce. London, 1761.

"

The origin of bitumens is an interefting queftion, concerning which naturalifts are not agreed, fome imagining that they effentially belong to the mineral kingdom, and others that they proceed originally from vegetable fubftances; we must allow this latter opinion to be the most probable, &c. See dict. of chemistry, tranflated from the French. London, printed for T. Cadell, 1777

It has been afferted that coals being fometimes produced from clay faturated by petroleum, may be found in any place or fituation where clay or argillaceous flate is to be met with, in ancient fimple or modern stratified mountains, as well as on, and in volcanic mountains, and that

henceforth