however, excepting one, I fhall decline discussing, as they either are of little importance, or have not been stated with fufficient precision. The objection I mean is, that in none of the experiments with animals, prepared after the manner of Mr. Galvani, are those appearances of attraction and repulfion to be observed, which are held to be the tests of the prefence of electricity. My answer to it is, that no such appearances can occur, in Mr. Galvani's experiments, consistently with the known requifities, for their success, and the established laws of electricity. For, as it has been proved, that there is naturally no disengaged electric fluid in the nerves and mufcles of animals, I except the torpedo and a few others, no signs of attraction and repulfion can be looked for in those substances, before the application of metals or charcoal, and after these have been applied, the equilibrium of the influence, agreeably to what has been already shewn, is never disturbed, unless means for its restoration beat the fame time afforded. Neither then ought figns of attraction and repulfion to be in this case presented, on the fuppofition that the influence is electrical; fince it is neceflary for the exhibition of fuch appearances, that bodies, after becoming electrical, should remain so during some sensible portion of time: it being well known, for example, that the paflage of the charge of a Leyden phial, from one of its furfaces to the other, does not effect the most delicate electrometer, fufpended from a wire or other fubstance, which forms the communicafion between them.

Such are the observations I mean at present to submit to the confider

ation of this Society, respecting the influence which incites the museles of animals to contract, in Mr. Galvani's experiments.

Obfervations on the Maritime Alps; from Beaumont's Travels through them.

THI

HINKING G that fome general deductions from the principal facts, or phenomena, mentioned in the course of this work may be expected of me, especially with respect to the theory of the formation of the irregular furface of the earth, at least of that wonderful part of it which I have so repeatedly explored, I have ventured to annex a few observations, which appear to me to merit the particular attention of philosophers, as likewise the con sequences which I think might be drawn from them.

of

I do not, however, mean to speak of what relates to the first and great revolution experienced by our globe at the formation of its continents: that is, at the epoch when the waters covered it about two thousand four hundred and fifty toifes, and which is nearly the prefent elevation of fome of the granitic peaks the, Alps, as Mont Blanc, Mont Rose; &c. In short, of the time when they were totally submerged by that element, and formed themfolves under that fluid, either by effect of crystallization or precipitation. I therefore only intend to touch on the phenomena which re late to the laft immerfion expегіеnс ed by our continent, and which ap pears to have been partial.

I. From the immenfe atterriffements, or land-accumulations, already formed, and which are continually increasing at the mouth of

or

tie Po; from the extreme variation or great variety exifting in the different ftrata of fand, pebbles, and vegetable earth, which now form the banks of that wonderful river; from the number of beds of maritime and fluviatiles, or river shells, which lie in fome places diftinct or separated, and in others confufedly mixed together, from Cremona to the fea: in fine, from the progreffive diminution which the velocity of the waters of the Po experience, in proportion as the lower valley of Lombardy enlarges and gets nearer the fea: I conclude doduce the following confequences. 1. That that part of the valley, which lies eastward of Cremona, cannot owe its origin or inereafe but to the quantities of earthy matter continually brought down and depofited by this river, which, to all appearances, were formerly infinitely more confiderable than at present. 2. That the fea once covered this fertile plain; and that the greatest part of Lombardy may be confidered as an encroachment made on that element, by a quantity of fragments detached from the primordial and fecondary chain of mountains, which were at first hurled by the fua in its laft retreat, and then carried along by the waters of the Po, which in fome degree still continues to depofit them, as before mentioned, by means of the frequent inundations caused by the overflowings of the Po in the confines of Ferrara and Bologna, which are increased by the eagerness of the inhabitants of those provinces, who unfortunately attempted to restrain the waters of that formidable river too foon by banks, dykes, &c.

II. From the direction of the valby of Lombardy, and of all the se

condary ones which terminate in it; from the extreme difference in the elevation of the head of these secondary valleys fituated at the foot of the Alps, and likewife from their number, compared to those on the weft and fouth-west of the fame mountains; from their irregular form, number, and great degree of abruptness, which exist likewise in the secondary and tertiary mountains on the eastern fide of the granitic peaks, in comparifon to those of the fame order on the western: in short, from the calcareous chain of. hills which furround all Lombardy: I think I may venture to conclude: 1. That the motion of the fea, in its first muțation or change, had a direction tending nearly from weit to eaft. 2. That at first it rose to a great height, which appears to be, fully proved by the calcareous mat, ter, containing maritime shells, now found lying on fome of the primitive rocks of the Alps. 3. That its motion and retreat, or fube fiding, were at first extremely rapid. 4. That the feas having rofe above the plains which form the high valleys of the Alps, it afterwards precipitated itself towards the eaft, and dug by its weight and ye locity the valleys which are at their feet, mutilating and chamfretting the secondary mountains which intercepted its pallage. 5. That the fea, having in process of time abated in its mation, had by its fediment formed the schistus and secondary mountains, which describe a kind of zone to the plain of Lombardy: in short, 6. That it is evident, that the fea remained or stopped a much longer time on the western fide than on the eastern.

III. From the enormous maffes of granite and primitive rock which [E4]

now lie isolated on the summit of several high calcareous, schistous, and fandy-hills in Piedmont, to which they have not the least analogy, I am naturally led to believe, 1. That the foil of the upper part of the valley of Lombardy was, when still covered or fubmerged by the fea, nearly as elevated as the summit of those hills are at prefent. 2. That thefe granitic mafles were most probably driven on the top of those hills by the accelerated action of the fea, as I have previoufly observed in a former part of my work, and left in that isolated state by the fame current, which, by gradually furrowing the foil in various directions, formed an innumerable quantity of small irregular valleys, which have, however, in general, their salient or prominent angles uniformly opposed to the concave ones.

IV. From the extreme degree of cold particularly experienced on the Cols.de Tende, Finestre, and Argentera, &c. though less elevated than Mont Cenis, I draw the following conclufion, viz. That the height and degree of elevation of the mountains, above the level of the fea, have lefs influence than that which they have above their valleys, in order to the absolute determination of the kind of climate which exifts on their fummit; provided, however, their height does not exceed one thousand or twelve hundred toises, that being nearly the zone in which the snow is per

manent.

V. From the irregular inclinations or directions so generally found in the beds or ftrata of the fecondary mountains, and from their abruptnefs, breaks, and quantity of heterogeneous matter fo frequently con

tained in their cavities, I am of opinion, 1. That those mountains could not have given way and funk, except at the time when their fummits were entirely fubmerged by the fea: indeed this fuppofition appears to be fully elucidated, by the calcareous matter containing marine foffils, which generally fill the vacuum formed by the different breaks of those mountains, and which is likewise sometimes found on their summits. 2. That they could not have thus broken or feparated, but from the effect of fubterraneous caverns formed in the interior of the globe, the vaults of which, from being progressively over-charged by a continual accumulation of calcareous particles depofited by the fea, have funk or given way, as, I flatter myself, I have in a former part of this work clearly demonstrated.

VI. From the number of mountains formed of grés, or fandstone, marne, or marl, and puddingstone, which lie on others of different species, such as granite, rockstone, &c. which likewife vary as to thereciprocal inclinations of their strata; alfo, from the irrregularity and extreme verticality in the ftrata of the mountains of schift, which even form a right angle with the horizon; in fine, from the general diforder or confufion which appear so confpicuous in the fecondary and tertiary mountains, fituated towards the west and fouth-west chain of the Alps, I am led to believe: 1. That the wonderful changes which our globe has experienced are entirely owing to the effects of fire and water, which have, at different epochs, powerfully and vifibly acted either together or feparate. 2. That

the

the continents have likewise been exposed to fimilar revolutions; and, in short, that the last great débâcle, or bouleversement, is not, by several centuries, of so remote a date as has been generally supposed.

VII. From the sandy hills which compose the valley described in the eighth chapter, containing different species of marine foffils, and which are as if inclosed or wedged in the midst of high calcareous mountains, which do not contain any; from the direction of this valley, which tends from north to fouth: from the petrified trees likewife found ten feet below the foil of the same valley, in the environs of Nice, resting on calcareous beds, the roots of which contained in their ramifications a quantity of marine fossils; I am induced to conclude, 1. That the sea, in its flow and gradual retreat, must have formed an extenfive gulph in the neighbourhood of Efcarene; and that the calcareous mountains, above alluded to, served as its eastern and western boundary. 2. That the summit of the fandy hills, which now form the inner valley, indicate as nearly as possible the elevation of the bottom of the gulph at that period. In fine, that the waters having afterwards effected their retreat in that place, from north to fouth, had, as it were, traced out the valley, which has fince been finished by the draining of that part of the sea which had been accidentally retained in some of the higher valleys, in confequence of having broken, by its weight and action, the calcareous barrier which for a time retained it. VIII. From the abrupt state of the calcareous mountains which border the Mediterranean coaft

from Nice to Savona; from their extreme height or elevation; from the depth of the fea which washes their bafis; as likewise from the direction of the rivers and valleys of that part of the chain, which is in general from north to fouth, and the vast number of gypsum quarries which are within a mile or two of the coast; I am led to suppose, 1. That the major part of the fecondary and tertiary chain of the Alps still remains covered by the fea. 2. That it appears probable that those mountains may extend to the islands of Corfica and Sardinia. In fine, that a number of these cal, careous mountains owe their abruptness to the last retreat of the fea, which had, by insensibly undermining their basis, occafioned part of their mass to detach and fall into the water, from their not having at that period acquired the same degree of confiftence which they now pofsess.

IX. From not having been able, with the greatest care and attention, to trace or difcover the least indication of volcanic operations from La Bouchette, near Genoa, to Mont Vifo, in Piedmont, which are the two mountains which terminate the maritime chain, I think myself authorised to say that there does not appear to have existed any volcanos in that part of the Alps, except in the valley of Fontaine du Temple, mentioned in the last chapter, and which, from not having been able properly to investigate, I cannot to a certainty venture to give my opinion.

These are the conclusions I deduce from the foregoing premifes and which I offer to the confideration of the public with some diffidenco