Reviewer's Charges." We are at a loss to conceive why a new edition has come forth."-"In every thing regarding the philosophy of chemistry, or the developement of general principles, it is ten years behind."-" Dr. Thomson's ten pages on electricity are also reprinted without alteration, though he surely might have taken the trouble, when he plunged so deeply into magnetism with Mr. Barlow, to have said something about the newly-discovered relations of that power and the electric." "His tautologies are endless, and his self-contradictions intolerable." وو Dr. Thomson's Answer.-" The new edition, I presume, was printed because the old had been sold. I am not aware that booksellers proceed in any other way." "I was obliged by my agreement to correct the press, and nothing more.' "Why it is necessary that the new edition should be decidedly superior to the old I do not perceive. Nor could any blame have been attached to me, though it had been printed verbatim from the fifth edition. But it is in reality decidedly superior; because it contains all the additions which had been made to the science in the interval between the two editions, so far as they were known to me.' "What is the discovery which I have omitted to notice?" "The assertion of the reviewers that it is ten years behind the present state of the science, is remarkable only for its shameful falsehood. Not a single proof is advanced in support of it, except that I took no notice of the newly-discovered connexion between electricity and magnetism. Now I was the first individual in Great Britain who made known Professor Oersted's discovery. It appeared in the Annals of Philosophy for October, 1820. Before I became acquainted with this discovery, the whole of the sixth edition of my System was printed. Indeed, as the book was published in October, or soon after, Mr. Brande must have been aware of the absurdity of the accusation; and he must have been induced to bring it forward because he had no real omission to point out." "The assertion that the second volume is a repetition of the first, is so palpably untrue, that the Reviewer must have been aware of its inaccuracy when he made it." "Not a single page of repetition is to be found in the book." Reviewers' Charges." He has no allusion whatever to the Natural History method of Mohs, which promises to do for the study of minerals what the sexual system did for plants;enabling a person, on taking up a specimen, to refer it to its peculiar class, order, genus, and species, till he discovers its. name and various relations.' "The only observable alteration, ‚VOL. IV. NO. XV. Y Y indeed, in his present article on mineralogy, is the erasure of Professor Jameson's name wherever it formerly occurred." Dr. Thomson's Answer." With respect to the system of Mohs, which has been adopted by Jameson in his last edition, I must confess myself an incompetent judge, because I do not understand it.” "Mr. Jameson's last edition is a cypher without a key. Under these circumstances, I thought myself obliged to omit my references to Jameson's system. I could not refer to the new edition, because I did not understand it. Thus circumstanced, I thought the best thing I could do, was to refer to Hoffmann's Mineralogy"-" from which most of Jamesons descriptions are taken. In this case, we decidedly think Dr. Thomson in the right. We also confess that we cannot comprehend much of the system of Mohs, and what we do understand appears altogether absurd. For instance, we find in his second order of minerals, atmospheric air, and atmospheric water, which are surely altogether out of place among minerals. What is more strange still, is, that while he makes rain to be a mineral, he takes no notice whatever of mineral waters! Lord Shaftesbury, in his advice to an author, very shrewdly remarks, that the surest and easiest way of becoming absurd is by rule and system; and we think Mohs, in this instance, strongly exemplifies the remark. Mr. Jameson, as an improvement on his master, introduces not mineral waters, which, by the way, are most unaccountably omitted in all the systems,-but " sea water," which he gravely informs us, both in his Manual and in the Supplement to the Encyclopædia Britannica, "is the water of the ocean"! Mohs, like Haüy and Romé de Lisle, makes great use of the crystalline forms of minerals. His first care, indeed, is to discover whether a mineral be crystallized as a rhomboid,—a pyramid,—or a prism, and upon this he founds its name. Chalk, for instance, he calls rhombohedral-calc-haloïde; flint, he calls, rhombohedral quarz, [not quartz] and sparry iron ore, he calls, brachy-typous-parachrose-baryte! Now to say nothing of the fact, that minerals are more commonly found without regular form than crystallized, the system must mislead a beginner into the notion, that minerals with such sounding names are something very different from those which he already knows; Prismatic Epsom salt, for example, would lead one to think that some peculiar variety of it was meant. Who, besides M. Mohs, could detect a rhomboidal crystal in a piece of chalk or of common lime-stone? It puts us in mind of another German system,-Von Feinagle's art of memory, with all its clumsy and lumbering parade of foolish associations, which everybody who has learned, is anxious to unlearn. We pitch M. Mohs and his system into the oblivion which they certainly merit. Reviewer's Charges.-" Dr. Thomson's attacks on the exalted reputation of the President of the Royal Society have long excited our surprise and indignation."-" But the full force of Dr. Thomson's hostility was exerted in depreciating the miner's safetylamp."-"The pages of Thomson's Annals became for some time thereafter the receptacle of much criticism and invective against the safety-lamp and its inventor."-" Of M. Gay-Lussac he says, We may pity the pusillanimity;' and he arraigns M. Thenard with downright dishonesty." Dr. Thomson's Reply." This impudent assertion the assertor knew to be false when he made it, and betrayed his knowledge of it in the very review in which it is contained. It is false that I have ever made any attack on the character or reputation of Sir H. Davy. On the contrary, I have always been in the habit of reckoning him among the number of my friends."—" I deny that I ever depreciated the safety-lamp. I did, indeed, when I heard Davy's account of his first lamp read to the Royal Society, express my opinion in my Journal, that it could not be used with safety."" As I honestly believed at the time that the lamp was hazardous, I think that I was bound to state my reasons for this opinion to the public."-" Almost immediately afterwards, Davy himself rejected his first lamp."—" Against his new lamp, I never in the Annals of Philosophy stated a single objection of my own, nor, so far as I can recollect, of any other person."-" My conduct with regard to the controversy' specting the person who had the merit of first introducing the miner's safety-lamp" "was fair and honourable," as "appears from this, that all the controversialists accused me of partiality to their adversaries."-"I must now draw the reader's attention to another particular, because it shows that this malignant writer was conscious of the inaccuracy and falsehood of his statements, and that he drew them up with no other view than to make up the appearance of a case, by jumbling together the most monstrous and inconsistent falsehoods."-" Had the reviewer quoted the passage" respecting Gay-Lussac "fairly," "it would have appeared, (contrary to his assertions,) that, so far from having attempted to deprive Davy of the honour of being the author of the modern theory respecting muriatic acid and chlorine, I have done him the most ample justice." re Reviewer's Charges." He drew up an analysis of a book (BARLOW's Essay on Magnetism) which he evidently did not un derstand, that he might have an opportunity of attacking the most illustrious scientific association in Europe, the Royal Society of London." Dr. Thomson's Reply." As for my observations on the council of the Royal Society, I have only to say, that, when I made them, I thought them just, and I still continue of the same opinion. As a Fellow of the Society, I thought myself not merely entitled, but called upon, to notice any little inadvertance on the part of the council." Reviewer's Charge." This hypothetical sentence is thrown at once on the student, without preface or commentary: The weight of an atom of oxygen in the subsequent part of this work will be denoted by, 1st, a volume of oxygen is equivalent to two atoms,' &c." Dr. Thomson's Reply.-"The reviewer must have been sadly put to it, in his search into mistakes, when he was driven to the necessity of creating them by misquotation, that he might have an opportunity of animadverting upon absurdities which originated with himself."-"The passage in my System is really as follows: The weight of an atom of oxygen in the subsequent part of this work will be denoted by 1. A volume of oxygen is equivalent to two atoms,' &c." Reviewer's Charges. In the Annals of Philosophy, April 1816, Dr. Thomson makes the equivalent of the phosphoric acid 3.634. In the Annals for August 1816, he makes it 3.5. In January following we find him affirming it to be 4.5, and that 3.5 is undoubtedly wrong. In October 1817, he returns to 4.5, confirming it by multiplied facts and reasonings. Finally, after Sir H. Davy, in 1818, ascertained the number to be 3.50, Dr. Thomson resumes 3.5, and claims the priority, by referring to the Annals for 1816.—(See Review, page 147, and URE's Dict. ART. Phosph. Acid.) Dr. Thomson's Reply." With respect to my mode of taking the specific gravity of phosphuretted hydrogen gas, the reviewer observes, This confession betrays poverty of invention and ignorance of the methods previously practised in such cases.' This observation from an individual, who, so far as is known to the public, never took the specific gravity of a gas in his life, and directed against me, who have determined the specific gravity of more than twenty gases, with a degree of care and accuracy sel If this is aimed at Dr. Ure, it is not true, for we ourselves have repeatedly seen him, in his public class-room, take the specific gravity of gases, and teach his pupils the method of doing it. dom equalled, and never surpassed, had surely been better spared. I affirm that my method is susceptible of greater accuracy than that which the reviewer insinuates that I did not know; and this I affirm, from having repeatedly tried both methods." We do not find, however, that Dr. Thomson has answered the reviewer's charge relating to his repeated change of the equivalent number of phosphoric acid, though we think even for this he might have found a reply. We must now leave the cause, of which we have impartially given the leading topics, to the judgment of our readers, repeating our regret that it should ever have come before the public in the garb of decided hostility. We observe that a fourth partyDr. A. B. Granville-has come forward, and seems to lean to the side of Dr. Thomson, in consequence of some previous misunderstanding of his own with Mr. Brande; but with this affair we shall not intermeddle. We hope that our impartiality may be proved by each of the parties accusing us of partiality to the other. British Review. ON THE SYMPTOMS AND HISTORY OF DISEASES. WE consider Dr. Marshall Hall as a very clever and ingenious writer, though he is somewhat fastidious about his title-pages, and generally changes them in his second editions so completely, that the unwary may easily be led to purchase the same book twice. His Essay on the Mimoses is now changed to an Essay on the Disorders of the Digestive Organs; and his account of Mimosis inquieta (which Mr. John Burns and the Edinburgh journalists were oldfashioned enough to consider as puerperal fever) is now changed to a Serious Morbid Affection. His able work on Diagnosis, which was found, we believe, to be rather heavy in sale, is now curtailed of its extended nosology and its tabular views, and appears under its present dapper form, of a thin octavo, on the * An Essay on the Symptoms and History of Diseases, considered chiefly in their relation to Diagnosis. By Marshall Hall, M. D. F. R. S. E. &c. London, 1822. |