superseded the necessity of it.-In 1823 I'again introduced the subject in my course at the Surrey Institution-when the experiments and theory noticed in my former letter to you, were offered in explanation-and I was induced to suppose my communication would not prove unacceptable, by the recent inquiries of some scientific friends who were anxious to know if I could explain the cause of so singular an effect-among whom was Mr. Lewthwaite, the writer of the letter alluded to by T. J.

I now turn to a more pleasing part of the subject, that of investigating experiments.

"Would suggest (continues T. J.) that Mr. W. should repeat the experiment with the water tube. I am disposed to think Mr. W. is in error, when he says the intensity (measured we are to suppose by a pith ball electrometer), indicated, was from 10° to 15°." The supposition in the parenthesis is perfectly correct, and I can assure T. J. I have too often repeated the experiment, and made too many notes upon the subject in conjunction with my electrical friends, to be in error. I have very frequently succeeded in the experiment with a quart jar, when the electrometer has indicated an intensity of only 10°, but not invariably; hence I stated in my letter," an intensity of from 10° to 15° is generally sufficient." Had I noticed all the minute peculiarities I have observed on this head, my communication would have been much too long for insertion, and as no particular point turned upon the question, I considered it sufficient to express myself in terms to be understood by an Electrician, without unnecessarily intruding upon your valuable pages. I must, however, inform T. J. that the success of the experiment, with a low degree of intensity, will greatly depend on the quality of the gunpowder, as well as the care taken to prevent the dissipation of the electrical fluid, for with very coarse powder I have been unable to perform the experiment at all.

T. J. lastly observes, "it would have been more satisfactory if the degree at which the jar spontaneously discharged itself, had also been stated." This I confess myself at a loss to comprehend, for I have always found the spontaneous discharge of a jar, when mounted in the usual way, to depend as much upon what may be termed casual circumstances, as any experiment connected with electricity. At one time I have seen a spontaneous discharge take place at 50°; at another, the same jar, with the same electrometer, has been charged to 90°, without a spontaneous discharge. This suggestion, if reduced to practice, would be rather an expensive one to me, as my jars are all furnished with internal paper rims, according to Mr. Singer's plan the metallic rods communicating with the inner coatings are passed through stout glass tubes, cemented New Series, VOL. VIII.

E

in the caps of the jars, and the uncoated surfaces are var nished, so that a spontaneous discharge seldom or ever takes place without fracturing the jar.

I am aware that the Pith Ball Electrometer is a very uncertain standard; and if my theory had depended on the degree of intensity required to produce the effect with a jar containing a given extent of coated surface, I should have used the balance electrometer, invented by Mr. W. S. Harris, of Plymouth, a description of which may be seen by referring to page 77 of "Observations on the Effects of Lightning on Floating Bodies, by W. S. Harris. London, 1823."

I trust T. J. will continue the experiments, which, when well matured, he has promised shall be submitted to your consideration; and, if he thinks I am in error, or has discovered any facts which may militate against my opinions, I will either most cheerfully answer them in the true spirit of philosophy, which teaches us "to agree to differ," or I will prove to him that I am not wedded to any system, and that no one would more readily sacrifice a favourite theory, at the shrine of truth, than myself. Should he, on the other hand, require any information on a subject which has been for some years my favourite study, I shall feel much pleasure in making the communication, if in my power. I am, Sir, your obedient servant, CHARLES WOODWARD.

ARTICLE XI.

Some Observations on Mr. Penn's Theory concerning the Formation of the Kirkdale Cave. By James Smithson, Esq. FRS.

(To the Editor of the Annals of Philosophy.)

June 10, 1824.

SIR, No observer of the earth can doubt that it has undergone very considerable changes. Its strata are everywhere broken and disordered; and in many of them are enclosed the remains of innumerable beings which once had life; and these beings appear to have been strangers to the climates in which

their remains now exist.

In a book held by a large portion of mankind to have been written from divine inspiration, an universal deluge is recorded. It was natural for the believers in this deluge to refer to its action, all, or many, of the phenomena in question; and the more so as they seemed to find in them a corroboration of the event.

Accordingly, this is what was done, as soon as any desire to account for these appearances on the earth became felt.

The success, however, was not such as to obtain the general assent of the learned; and the attempt fell into neglect and oblivion.

Able hands have lately undertaken the revival of this system; Mr. Penn has endeavoured to reconcile it with the facts of the Kirkdale Cave, which appeared to be strongly inimical to it.

nor

Acquainted with Mr. Penn's opinions only from the "Analysis of the Supplement to the Comparative Estimate" in the Journal of the Royal Institution for January, not having seen this Supplement itself, the Comparative Estimate, even a review of this in a former number of the Journal, and knowing of Mr. Buckland's Reliquia Diluviana, only the account of the Kirkdale Cave published in the Philosophical Transactions for 1822, I have hesitated long about communicating the present observations, which presented themselves during the perusal of the above-mentioned slender abstract.

I have yielded to a sense of the importance of the subject in more than one respect, and of the uncertainty when I shall acquire ampler information at more voluminous sources-to a conviction that it is in his knowledge that man has found his greatness and his happiness, the high superiority which he holds over the other animals who inhabit the earth with him, and consequently that no ignorance is probably without loss to him, no error without evil, and that it is therefore preferable to urge unwarranted doubts, which can only occasion additional light to become elicited, than to risk by silence to let a question settle to rest, while any unsupported assumptions are involved in it.

If I rightly apprehend Mr. Penn's ideas, they are these: Secondary limestones were originally in a soft state. The waters of the deluge while elevated above England, deposited on it a layer, or bed, of "a soft and plastic" calcareous

matter.

On their departure from the earth, by flowing away towards the north, they floated over England the carcases of a number of tropical animals, clustered together into great masses.

These masses became buried in the calcareous mud.

On the sinking of the waters of the deluge below the surface of England, the bed of calcareous mud began to dry, and on doing so completely, became the present Kirkdale rock.

The clustered animal bodies enclosed in the calcareous paste, by putrifying, evolved a great quantity of gas, which forced the limestone paste in all directions from them, and thus generated the Cave in which Mr. Buckland found their bones.

Soft State of Secondary Limestones.

That secondary limestones have been in a state to admit fo

reign bodies into their substance, their existence in it is evidence.

Every shell and stone on the beach tells by its rounded form the attrition to which it is subject at each flood and ebb of the tide; and that a subtil powder is abraded from it which is collected somewhere.

From the immense multitudes of marine bodies which exist in some of these limestones, from others consisting in fact entirely of them, from in general little or nothing but calcareous matter being present, it becomes highly probable that it is to the calcareous part of marine animals, more or less comminuted, that secondary limestones owe their origin.

Deposition of the Calcareous Mud.

The waters of the deluge had not, surely, either a duration or power, to obtain the matter of this supposed layer of mud. No shores any longer existing, shells could not be pulverised by the beat of the wave, for it is not deep under water that such destruction is effected; nor, was it so, would the short period of a year have been sufficient to produce the material of all the secondary limestones of the earth?

To have harrowed up this matter from the depths of the ocean, would have required an agitation of the waters, which nothing warrants us in giving to them, which every thing denies their having had.

No hurricanes, no tempestuous winds, no swollen billows, are recorded. To drown mankind they were superfluous. A wind having arisen at the termination of the calamity tells that none existed before; and this wind must have been a most gentle one, a very zephyr. A vessel, bulky beyond all the efforts of imagination to figure, so laden, so manned, could not have lived in any agitated sea, least in one which out-topped the Alps, and the Andes, all that could curb its fury, and mitigate its violence.

Had the ark not foundered, which is impossible, what yet had become of the millions which its sides enclosed? Few had survived to repair the effects of the divine wrath.

The waters must have been at rest when the ark continued stationary for many months on the mountains of Ararat.

Nor, do the agitations of a sea extend far below its surface. What navigator has told of the storm in which the sea became thick with its own sediments?

But had such a deposit been made on our island, it would not have continued on it. Standing like a little turret in the bosom of the waters, each agitation of them would have precipitated part of it down its sides. Their gigantic tides must alone have washed it away, and on the rush of their final departure, not a vestige of it could possibly have remained behind.

If the waters of the deluge placed a bed of calcareous matter on England and Germany, they must have done so over the entire earth. It must have been an universal stratum.

Yet so total was the deficiency of it at Botany Bay, that the first settlers, for the very little lime which a few structures of immediate necessity required, were compelled, though spare as were the hands, and much as they were wanted for other purposes, laboriously and tediously, to collect shells along the beach. Where a limestone nodule was so anxiously sought and could not be found, great strata could not be near.

But the sediment of the deluge waters would not be mere calcareous matter. It must have consisted of every thing which they could receive, suspend, and deposit.

If over the earth were spread such a layer of mire, Noah and the animals could not have landed upon it. Or had they not sunk into it and been smothered; where yet had the weak found refuge from the voracious; where had the herbivorous found food?

What a time must have elapsed before Noah could cultivate the vine! Nor is it from such a soil that the wine would have intoxicated the holy Patriarch. Had things so been, Ham never had offended, nor Canaan incurred the fatal curse.

Sinking of the Bodies into the Mud.

Supposing, however, such a bed of "soft and plastic" calcareous matter deposited by the waters on England, the immersion of the bodies into it is of no small difficulty.

Animal bodies bloated with gas from decay, which water had "floated on its surface," are not easily conceived to have displaced a stony powder of a specific gravity of 2.7, and to have fallen below it.

"Turbulent vortices," which are imagined to have lent their aid on the occasion, would have disseminated the clustered animals, and dispersed the powdery stratum.

That the bodies should in every case have descended into the calcareous pulp, in one unbroken group; that in none a fragment, even a lock of hair, should have parted from the putrid mass, and stopped by the way, cannot certainly plead probability in its favour. Yet what cabinet shows even the slenderest bone of a water-rat bedded in the solid stone? What limestone stratum has astonished the learned, by presenting them, in its substance, with an antediluvian hyæna's bristles, or lion's mane ?

Formation of the Cave.

If the limestone pulp was too thin, the gas would pass through it and escape, and the pulp fall back upon the bodies; if too thick, the elastic force of the gas would be insufficient to repel it from them. A precise point of induration, at