LIV. D.'s Second Reply to C. on Mr. HERAPATH's Theory.

To the Editors of the Philosophical Magazine and Journal. GENTLEMEN,— My last clearly established, against Mr. Phillips's correspondent C., some very inexcusable misrepresentations of Mr. Herapath. Instead of answering these charges candidly, he has endeavoured to divert the attention of his readers to the twisting and torturing of some of my expressions for the mere purpose of trying to retaliate. After he has thus consumed three or four months, and has carefully compared the whole of my quotations, examined the position of every word, and calculated the propriety of every comma; he has at length, amidst his amplified exaggeration, been obliged to acknowledge, in one of his powerful instances, that "as the tone and emphasis of the sentences are changed, rather than the sense, it is not of material consequence!"

C., Annals for December, p. 423, says, "How Mr. H. proves 'that the intensity of the stroke is the force with which each of the balls is acted on in a direction opposite to that in which it came at the time of the contact,' I am at a loss to discover." "The intensity of the force is equal to the sum of the momenta' with which both balls come in contact.'" 6 In quoting the substance of the last of these sentences, Annals for May, p. 358, "I observed," C. says, "that the intensity of the stroke between two bodies moving towards opposite parts is equal to the sum of their momenta.' Surely nothing can be plainer or fairer than this quotation, particularly when all I have said in the same paragraph and preceding page be considered; yet C. in his reply, Annals for September, pp. 207 and 208, flies out into a violent philippic, and declares, because I had not written "equal balls" and "equal momenta," that my quotation" is absolutely false," and a "wilful misstatement." When I first read these fearful words, I was surprised at the charge; but when I came to examine the real groundless foundation of them,

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Obstupui, steteruntque comæ, et vox faucibus hæsit." For it is not the least curious part of this affair, that in the whole paragraph, upwards of a page and a quarter, which contains C.'s much-injured sentence, he has not once used the term "equal balls," or "equal momenta," except in two quotations from Mr. Herapath, both a long way before the sentence in question. So great a reason therefore has C. to complain, that the misrepresentation, if there were any, would have been of Mr. H. rather than of himself. However, if in this matter we cannot perceive the justice of C.'s complaint, we must at

least

least admire his ingenuity; for so cleverly has he drawn his case, that any one who reads that alone would be apt to cry out with Demosthenes, "Now indeed do I hear the voice of one that is injured."

"Ex

Page 201 of C.'s reply presents us with another instance of this kind, much too pleasant to pass over in silence. periment," says C. in his first attack, p. 419, "has clearly shown that caloric, or the immediate cause of heat, whatever it may be called, cannot be destroyed. However, under particular circumstances, it may become for a time imperceptible, it can again be developed, and so be shown to have continued its existence: if, therefore, heat and motion be identical, motion cannot be destroyed." A plainer allusion than this to the disappearance and reappearance of heat in the changes of state, and a clearer objection to the theory of heat by motion, from its assumed inability to explain such phænomena, could hardly be expected from this writer. As such no doubt it would have been allowed to pass, and have been ranked amongst C.'s unanswerable objections, had I not unhappily shown that C., before he published this, had seen the Number containing Mr. H.'s theory of the changes of state, his mathematical computations of the various dependent phænomena, &c., and consequently that C.'s observations were a gross attempt to misrepresent. Finding however the case a little too clear against him, C. turns round in his reply, and by a long list of unqualified "I never dids" and "I did nots" boldly denies both object and allusion; but unfortunately in the close admits, he "intended to show that the indestructibility of caloric," in the changes of state of course, "is a strong argument to prove it cannot be merely motion." As a finale to such a novelty of consistency, C. should have added: "Mallem mori quàm mutare."

The liberal use C. makes of the polite terms "false,” “absolutely false," &c. I should have left unnoticed, had he not made such elevated expressions the agents for depriving his own character of the imputation of a dishonest disputant to fix it on mine.

That I have held up to ridicule absurdities legitimately drawn from his notions, is true. This however is not my fault, but his. If a man be so weak as to meddle with subjects above his reach, and imprudent enough to publish his crudities, he must expect to be laughed at. As to making "false" quotations for the purpose of wilful misrepresentation, I have not done it, and this C. well knows. Nor has he, with all the assistance of invention, and the wide latitude which the numerous and in some instances nonsensical deviations of the printed from the MS. reply have afforded him, been able to make out

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one such a case. This, in the present state of C.'s writings, is all the notice I can take of his baseless accusation.

Every person, who takes the pains to read C.'s last communication, can easily discover the "honourable" means to which he has had recourse to shift from the charges of palpable misrepresentation which I have in my former reply so clearly proved. Before I proceed "to examine the reasoning" which he calls mathematical, I will extract from C.'s "reply" a few specimens out of a countless number of that sort of truth, "which," one would have thought, "his honourable feelings, intelligence, and integrity, would have alike disdained." If they can do nothing else, they will serve to show how impossible it is for a person of C.'s "integrity" to depart from that kind of rectitude to which he has been accustomed. In the Annals for September, p. 198, C. giving a quotation from my first reply makes me say, "In more than one instance C. has not been over delicate in this respect." The original has the phrase “I think” immediately after " has." But this omission, which merely converts a matter of opinion into an absolute assertion, is, I presume, in C.'s system of no consequence, especially as it happens to be in the very page and paragraph, in which he is trying to call in question my "moral deficiency" for a misrepresentation of which indeed his own imagination is the author. I pass over in the same pages his "honourable" suppression of the principal part of what I had (Annals, April, p. 292,) advanced to prove his having "falsely" charged Mr. H. with attributing to hard bodies the properties of elastic, and his insinuating that what he has quoted is all that I had advanced; his curious quotations from Newton and Hutton to support a consequence of a property, instead of the property itself; his creditable quibble on the word almost; his very justifiable statement that D. "admits that Mr. H. advisedly used the one word instead of the other;" his edifying attempt to get rid of his discovery of having proved truth error; together with many things of the same stamp in the first few pages only of his reply, not because I think they would be unimportant or not discreditable to a person who values his reputation, but because they appear in fact, in C.'s reply, like the glimmering of nebulæ stars amidst an endless constellation of glowing violations of facts; I pass, I say, these things over, not for their real but their relative unimportance. I will now, however, adduce a few specimens, that will not want the aid of comment to illustrate their object and their origin. They will besides set at rest the claims of C. to veracity, to "integrity," and to "honourable feelings." "But what has this to do," says C., Annals, September, p. 211, "with

Mr.

Mr. H.'s proposition, 'that the VELOCITIES of the moving bodies have no effect on the INTENSITIES of the strokes?" Let us here observe that the part of the quotation in Italics is what C, has given between double inverted commas, and therefore intended to be a verbatim, I presume, transcript of one of Mr. Herapath's "propositions." The fact however is, there is no such a thing in words, sense, or import; and not merely in Mr. H.'s propositions, but not even in any part of his printed writings that I can perceive. His first Prop., which seems to be the only one relating to this subject, says: "If two bodies absolutely hard impinge on one another, the DURATION or SMARTNESS of the stroke is independent of the velocity of contact." This is all that he says of this subject in his "propositions;" and in a Cor. to the first Prop. he says: "Hence we gather, that in perfectly hard bodies the intensity of the impulse depends on the violence or momentum of contact, and is independent of the velocity of contact, except inasmuch as it is augmented or diminished by that velocity." Here, therefore, C. not merely gives to Mr. H. words which he never used, and a "proposition" which he never wrote, but actually a meaning totally different from any thing he ever published; and this for the mere purpose of creating a groundless opposition between Dr. Hutton, Prof. Playfair, and Mr. Herapath. If C. can edge out of this without a frank avowal of " wilful misrepresentation," let him; I shall be happy to see his manœuvres.

So much at home does C. appear in misrepresentations, and so easily and rapidly do they flow from him, that, even after he had indulged in the above glaring specimen, which one might have thought would last him through a few pages at least, he could not finish the subsequent paragraph in the same page without presenting us with another. As this is however one of C.'s ordinary aberrations from truth, I will leave it without further comment. In the very next page C. informs us, "D. says that the velocity of B after the stroke is = A a B 99 Turning to p. 362, Annals for May, from which C. A+B pretends to have extracted this idea, I find I said: "the motion it" (that is, the momentum B) "acquires by the stroke = Aa B 39 In the former case of misrepresentation C.. put in Mr. H.'s mouth" intensity of the stroke" for "duration of the stroke," that is, violence for time; and he has now thought proper to mistake for me velocity for momentum; and this at a time when he is trying to demonstrate a paradox I had proposed. Of course his demonstration must be very complete and very unique.

A+B'

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One more example shall be all of this kind with which I will trouble your readers. At p. 406 of his first paper Mr. Herapath, among a variety of other numerical comparisons of his theory with experimental facts, mentions the results of some calculations on the mixtures of mercury at given temperatures and in given proportions. In all that he has here said of the subject, he has not so much as hinted at his method of deducing the principles on which he founds his calculations from his theory; as any one who chooses to take the trouble of turning to the place may convince himself. Mr. H. has indeed rested satisfied in this place with giving a simple statement of the results of his calculations, without once adverting to his mode of theoretical deduction; but in the third Prop., and its scholium, of his second paper, he has entered into both theory and calculations at length. Now it is a circumstance worthy of observation, a fact highly illustrative of C.'s "honour" and "integrity," that he has omitted even to allude to the theory in Mr. H.'s second paper; and has quoted from the first the simple results, the mere calculations of the case in question, as a specimen of the "mode of reasoning," which he calls "reasoning in a circle," that Mr. Herapath pursues, for the purpose, I suppose he means, of misleading his readers.

To amplify these examples of C.'s regard to truth, which I have selected from a multitude of the same kind, is impossible. However, as there may be those who would hardly admit there can be a person that could in the face of facts, with unblushing confidence, and amidst the most palpable evidence to the contrary, wilfully be guilty of such misrepresentations as I have adduced, they may in charity be inclined to attribute them to a confused intellect. They may imagine, and account for these things by supposing, that C. cannot clearly discriminate between opinion and assertion, between one expression and another, between time and a blow, between momentum and velocity, or between narration and argument; and such ideas they may confirm by showing, that C. confounds effects with causes, calls his own simple statements reasoning, and tells us, as his own discovery I suppose, that Newton gives his sentiments of heat and gravity in a manner which "affords no pretence to consider them his opinions!!" To such charitable proofs of a cloudy mind, of course I can say nothing; and I must, I presume, therefore allow, that what in another would be considered the effects of intention, the want of "honour" and "integrity," must in C. be the natural consequences of an unnatural intellect.

We have now said enough to give a tolerable idea of the Vol. 60. No. 294. Oct. 1822. confidence

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