[Without date, but supposed to be in 1789.]

"MY DEAR FRIEND,

"During our long acquaintance you have shown many instances of your regard for me, yet I must now desire you to add one more to the number, which is that if you publish your ingenious discourse on the _moral sense_, you will totally omit and suppress that extravagant encomium on your friend Franklin, which hurt me exceedingly in the unexpected hearing, and will mortify me beyond conception if it should appear from the press.

"Confiding in your compliance with this earnest request, I am ever, my dear friend, yours most affectionately,

B. FRANKLIN."

_To Miss Catharine Louisa Shipley._

"Philadelphia, April 27, 1789.

"It is only a few days since the kind letter of my dear young friend, dated December 24, came to my hands. I had before, in the public papers, met with the afflicting news that letter contained. That excellent man has then left us! his departure is a loss, not to his family and friends only, but to his nation and to the world: for he was intent on doing good, had wisdom to devise the means, and talents to promote them. His sermon before the Society for Propagating the Gospel, and "_his speech intended to be spoken_," are proofs of his ability as well as his humanity. Had his counsels in those pieces been attended to by the ministers, how much bloodshed might have been prevented, and how much expense and disgrace to the nation avoided!

"Your reflections on the constant calmness and composure attending his death are very sensible. Such instances seem to show that the good sometimes enjoy, in dying, a foretaste of the happy state they are about to enter.

"According to the course of years, I should have quitted this world long before him: I shall, however, not be long in following. I am now in my eighty-fourth year, and the last year has considerably enfeebled me, so that I hardly expect to remain another. You will then, my dear friend, consider this as probably the last line to be received from me, and as a taking leave.

"Present my best and most sincere respects to your good mother, and love to the rest of the family, to whom I wish all happiness; and believe me to be, while I _do_ live, yours most affectionately,

"B. FRANKLIN."

_To_ * * *.

(Withoute date.)

"DEAR SIR,

"I have read your ma.n.u.script with some attention. By the argument it contains against a particular Providence, though you allow a general Providence, you strike at the foundations of all religion. For without the belief of a Providence that takes cognizance of, guards and guides, and may favour particular persons, there is no motive to worship a Deity, to fear its displeasure, or to pray for its protection. I will not enter into any discussion of your principles, though you seem to desire it. At present I shall only give you my opinion, that though your reasonings are subtle, and may prevail with some readers, you will not succeed so as to change the general sentiments of mankind on that subject, and the consequence of printing this piece will be, a great deal of odium drawn upon yourself, mischief to you, and no benefit to others. He that spits against the wind, spits in his own face. But were you to succeed, do you imagine any good would be done by it? You yourself may find it easy to live a virtuous life without the a.s.sistance afforded by religion; you having a clear perception of the advantages of virtue and the disadvantages of vice, and possessing a strength of resolution sufficient to enable you to resist common temptations. But think how great a portion of mankind consists of weak and ignorant men and women, and of inexperienced, inconsiderate youth of both s.e.xes, who have need of the motives of religion to restrain them from vice, to support their virtue, and retain them in the practice of it till it becomes _habitual_, which is the great point of its security. And perhaps you are indebted to her originally, that is, to your religious education, for the habits of virtue upon which you now justly value yourself. You might easily display your excellent talents of reasoning upon a less hazardous subject, and thereby obtain a rank with our most distinguished authors. For among us it is not necessary, as among the Hottentots, that a youth to be raised into the company of men should prove his manhood by beating his mother. I would advise you, therefore, not to attempt unchaining the tiger, but to burn this piece before it is seen by any other person, whereby you will save yourself a great deal of mortification from the enemies it may raise against you, and, perhaps, a great deal of regret and repentance. If men are so wicked _with religion_, what would they be if _without it_? I intend this letter itself as a _proof_ of my friendship, and, therefore, add no _professions_ to it; but subscribe simply yours,

B. FRANKLIN."

_Copy of the last Letter written by Dr. Franklin._

"Philadelphia, April 8, 1790.

"SIR,

"I received your letter of the 31st of last past relating to encroachments made on the eastern limits of the United States by settlers under the British government, pretending that it is the _western_, and not the _eastern_ river of the Bay of Pa.s.samaquoddy which was designated by the name of St. Croix, in the treaty of peace with that nation; and requesting of me to communicate any facts which my memory or papers may enable me to recollect, and which may indicate the true river which the commissioners on both sides had in their view to establish as the boundary between the two nations.

"Your letter found me under a severe fit of my malady, which prevented my answering it sooner, or attending, indeed, to any kind of business. I now can a.s.sure you that I am perfectly clear in the remembrance that the map we used in tracing the boundary was brought to the treaty by the commissioners from England, and that it was the same that was published by _Mitch.e.l.l_ above twenty years before. Having a copy of that map by me in loose sheets, I send you that sheet which contains the Bay of Pa.s.samaquoddy, where you will see that part of the boundary traced. I remember, too, that in that part of the boundary we relied much on the opinion of Mr. Adams, who had been concerned in some former disputes concerning those territories. I think, therefore, that you may obtain still farther light from him.

"That the map we used was Mitch.e.l.l's map, Congress were acquainted at the time, by letter to their secretary for foreign affairs, which I suppose may be found upon their files.

"I have the honour to be, with the greatest esteem and respect, sir, your most obedient and most humble servant,

"B. FRANKLIN.

"To Thomas Jefferson, } "Secretary of State of the United States."}

PHILOSOPHICAL SUBJECTS.

_To the Abbe Soulavie._[35]

[35] Occasioned by his sending me some notes he had taken of what I had said to him in conversation on the Theory of the Earth. I wrote it to set him right in some points wherein he had mistaken my meaning.--B. F.

_Theory of the Earth._--Read in the American Philosophical Society, November 22, 1782.

Pa.s.sy, September 22, 1782.

I return the papers with some corrections. I did not find coal mines under the calcareous rocks in Derbyshire. I only remarked, that at the lowest part of that rocky mountain which was in sight, there were oyster sh.e.l.ls mixed in the stone; and part of the high county of Derby being probably as much above the level of the sea as the coal mines of Whitehaven were below it, seemed a proof that there had been a great _boulvers.e.m.e.nt_ in the surface of that island, some part of it having been depressed under the sea, and other parts, which had been under it, being raised above it. Such changes in the superficial parts of the globe seemed to me unlikely to happen if the earth were solid to the centre. I therefore imagined that the internal parts might be a fluid more dense, and of greater specific gravity than any of the solids we are acquainted with, which therefore might swim in or upon that fluid.

Thus the surface of the globe would be a sh.e.l.l, capable of being broken or disordered by the violent movements of the fluid on which it rested.

And as air has been compressed by art so as to be twice as dense as water, in which case, if such air and water could be contained in a strong gla.s.s vessel, the air would be seen to take the lowest place, and the water to float above and upon it; and as we know not yet the degree of density to which air may be compressed, and M. Amontons calculated that its density increasing as it approached the centre in the same proportion as above the surface, it would, at the depth of---- leagues, be heavier than gold; possibly the dense fluid occupying the internal parts of the globe might be air compressed. And as the force of expansion in dense air, when heated, is in proportion to its density, this central air might afford another agent to move the surface, as well as be of use in keeping alive the subterraneous fires; though, as you observe, the sudden rarefaction of water coming into contact without those fires, may also be an agent sufficiently strong for that purpose, when acting between the inc.u.mbent earth and the fluid on which it rests.

If one might indulge imagination in supposing how such a globe was formed, I should conceive, that all the elements in separate particles being originally mixed in confusion, and occupying a great s.p.a.ce, they would (as soon as the almighty fiat ordained gravity, or the mutual attraction of certain parts and the mutual repulsion of others, to exist) all move to their common centre: that the air, being a fluid whose parts repel each other, though drawn to the common centre by their gravity, would be densest towards the centre, and rarer as more remote; consequently, all matters lighter than the central parts of that air and immersed in it, would recede from the centre, and rise till they arrived at that region of the air which was of the same specific gravity with themselves, where they would rest; while other matter, mixed with the lighter air, would descend, and the two, meeting, would form the sh.e.l.l of the first earth, leaving the upper atmosphere nearly clear. The original movement of the parts towards their common centre would naturally form a whirl there, which would continue upon the turning of the new-formed globe upon its axis, and the greatest diameter of the sh.e.l.l would be in its equator. If by any accident afterward the axis should be changed, the dense internal fluid, by altering its form, must burst the sh.e.l.l and throw all its substance into the confusion in which we find it. I will not trouble you at present with my fancies concerning the manner of forming the rest of our system. Superior beings smile at our theories, and at our presumption in making them. I will just mention, that your observations on the ferruginous nature of the lava which is thrown out from the depths of our volcanoes, gave me great pleasure. It has long been a supposition of mine, that the iron contained in the surface of the globe has made it capable of becoming, as it is, a great magnet; that the fluid of magnetism perhaps exists in all s.p.a.ce; so that there is a magnetical north and south of the universe, as well as of this globe, and that, if it were possible for a man to fly from star to star, he might govern his course by the compa.s.s; that it was by the power of this general magnetism this globe became a particular magnet. In soft or hot iron the fluid of magnetism is naturally diffused equally; when within the influence of the magnet it is drawn to one end of the iron, made denser there and rarer at the other. While the iron continues soft and hot, it is only a temporary magnet; if it cools or grows hard in that situation, it becomes a permanent one, the magnetic fluid not easily resuming its equilibrium.

Perhaps it may be owing to the permanent magnetism of this globe, which it had not at first, that its axis is at present kept parallel to itself, and not liable to the changes it formerly suffered, which occasioned the rupture of its sh.e.l.l, the submersions and emersions of its lands, and the confusion of its seasons. The present polar and equatorial diameters differing from each other near ten leagues, it is easy to conceive, in case some power should shift the axis gradually, and place it in the present equator, and make the new equator pa.s.s through the present poles, what a sinking of the waters would happen in the equatorial regions, and what a rising in the present polar regions; so that vast tracts would be discovered that now are under water, and others covered that are now dry, the water rising and sinking in the different extremes near five leagues. Such an operation as this possibly occasioned much of Europe, and, among the rest, this mountain of Pa.s.sy on which I live, and which is composed of limestone, rock, and seash.e.l.ls, to be abandoned by the sea, and to change its ancient climate, which seems to have been a hot one. The globe being now become a perfect magnet, we are, perhaps, safe from any change of its axis. But we are still subject to the accidents on the surface, which are occasioned by a wave in the internal ponderous fluid; and such a wave is producible by the sudden violent explosion you mention, happening from the junction of water and fire under the earth, which not only lifts the inc.u.mbent earth that is over the explosion, but, impressing with the same force the fluid under it, creates a wave that may run a thousand leagues, lifting, and thereby shaking, successively, all the countries under which it pa.s.ses. I know not whether I have expressed myself so clearly as not to get out of your sight in these reveries. If they occasion any new inquiries, and produce a better hypothesis, they will not be quite useless. You see I have given a loose to imagination; but I approve much more your method of philosophizing, which proceeds upon actual observation, makes a collection of facts, and concludes no farther than those facts will warrant. In my present circ.u.mstances, that mode of studying the nature of the globe is out of my power, and therefore I have permitted myself to wander a little in the wilds of fancy. With great esteem,

B. FRANKLIN.

P.S.--I have heard that chymists can by their art decompose stone and wood, extracting a considerable quant.i.ty of water from the one and air from the other. It seems natural to conclude from this, that water and air were ingredients in their original composition; for men cannot make new matter of any kind. In the same manner, may we not suppose, that when we consume combustibles of all kinds, and produce heat or light, we do not create that heat or light, but decompose a substance which received it originally as a part of its composition? Heat may be thus considered as originally in a fluid state; but, attracted by organized bodies in their growth, becomes a part of the solid. Besides this, I can conceive, that in the first a.s.semblage of the particles of which the earth is composed, each brought its portion of loose heat that had been connected with it, and the whole, when pressed together, produced the internal fire that still subsists.

_To Dr. John Pringle._

ON THE DIFFERENT STRATA OF THE EARTH.

Craven-street, Jan. 6, 1758.

I return you Mr. Mitch.e.l.l's paper on the strata of the earth[36] with thanks. The reading of it, and the perusal of the draught that accompanies it, have reconciled me to those convulsions which all naturalists agree this globe has suffered. Had the different strata of clay, gravel, marble, coals, limestone, sand, minerals, &c., continued to lie level, one under the other, as they may be supposed to have done before those convulsions, we should have had the use only of a few of the uppermost of the strata, the others lying too deep and too difficult to be come at; but the sh.e.l.l of the earth being broke, and the fragments thrown into this oblique position, the disjointed ends of a great number of strata of different kinds are brought up to day, and a great variety of useful materials put into our power, which would otherwise have remained eternally concealed from us. So that what has been usually looked upon as a _ruin_ suffered by this part of the universe, was, in reality, only a preparation, or means of rendering the earth more fit for use, more capable of being to mankind a convenient and comfortable habitation.

[36] The paper of Mr. Mitch.e.l.l, here referred to, was published afterward in the Philosophical Transactions of London.

B. FRANKLIN.

_To Mr. Bowdoin._