1Hooke’s Posthumous Works. Lond. 1705.—p. 472 and p. 458.

2Wealth of Nations, book i. chap. i. p. 15.

3On this subject, we cannot forbear citing a passage from one of the most profound but at the same time popular writers of our time, on a subject unconnected it is true with our own, but bearing strongly on the point before us. “But, if science be manifestly incomplete, and yet of the highest importance, it would surely be most unwise to restrain enquiry, conducted on just principles, even where the immediate practical utility of it was not visible. In mathematics, chemistry, and every branch of natural philosophy, how many are the enquiries necessary for their improvement and completion, which, taken separately, do not appear to lead to any specifically advantageous purpose! how many useful inventions, and how much valuable and improving knowledge, would have been lost, if a rational curiosity, and a mere love of information, had not generally been allowed to be a sufficient motive for the search after truth!”—Malthus’s Principles of Political Economy, p. 16.

4?????, ratio, reason.

5?????, verbum, a word.

6It were much to be wished that navigators would be more cautious in laying themselves open to a similar censure. On looking hastily over a map of the world we see three Melville Islands, two King George’s Sounds, and Cape Blancos innumerable.

7Young. Lectures on Nat. Phil. ii. 627. See also Phil. Trans. 1801–2.

8Captain Basil Hall, R.N.

9We must caution our readers who would assure themselves of it by trial, that it is an experiment of some delicacy, and not to be made without several precautions to ensure success. For these we must refer to our original authority (Fresnel. MÉmoire sur la Diffraction de la Lumiere, p. 124.); and the principles on which they depend will of course be detailed in that volume of the Cabinet CyclopÆdia which is devoted to the subject of Light.

10Little reels used in cotton mills to twist the thread.

11Such a block would weigh between four and five hundred thousand pounds. See Dr. Kennedy’s “Account of the Erection of a Granite Obelisk of a Single Stone about Seventy Feet high, at Seringapatam.”—Ed. Phil. Trans. vol. ix, p. 312.

12Dr. Coindet of Geneva.

13Journal of a Voyage to the South Seas, &c. &c. under the Command of Commodore George Anson, in 1740–1744, by Pascoe Thomas, Lond. 1745, So tremendous were the ravages of scurvy, that, in the year 1726, admiral Hosier sailed with seven ships of the line to the West Indies, and buried his ships’ companies twice, and died himself in consequence of a broken heart. Dr. Johnson, in the year 1778, could describe a sea-life in such terms as these:—“As to the sailor, when you look down from the quarter deck to the space below, you see the utmost extremity of human misery, such crowding, such filth, such stench!”—“A ship is a prison with the chance of being drowned—it is worse—worse in every respect—worse room, worse air, worse food—worse company!” Smollet, who had personal experience of the horrors of a seafaring life in those days, gives a lively picture of them in his Roderick Random.

14Lemon juice was known to be a remedy for scurvy far superior to all others 200 years ago, as appears by the writings of Woodall. His work is entitled “The Surgeon’s Mate, or Military and Domestic Medicine. By John Woodall, Master in Surgery London, 1636,” p. 165. In 1600, Commodore Lancaster sailed from England with three other ships for the Cape of Good Hope, on the 2d of April, and arrived in Saldanha Bay on the 1st of August, the commodore’s own ship being in perfect health, from the administration of three table-spoonsfull of lemon juice every morning to each of his men, whereas the other ships were so sickly as to be unmanageable for want of hands, and the commander was obliged to send men on board to take in their sails and hoist out their boats. (Purchas’s Pilgrim, vol. i. p. 149.) A Fellow of the college, and an eminent practitioner, in 1753 published a tract on sea scurvy, in which he adverts to the superior virtue of this medicine; and Mr. A. Baird, surgeon of the Hector sloop of war, states, that from what he had seen of its effects on board of that ship, he “thinks he shall not be accused of presumption in pronouncing it, if properly administered, a most infallible remedy, both in the cure and prevention of scurvy.” (Vide Trotter’s Medicina Nautica.) The precautions adopted by captain Cook in his celebrated voyages, had fully demonstrated by their complete success the practicability of keeping scurvy under in the longest voyages, but a uniform system of prevention throughout the service was still deficient.

It is to the representations of Dr. Blair and sir Gilbert Blane, in their capacity of commissioners of the board for sick and wounded seamen, in 1795, we believe, that its systematic introduction into nautical diet, by a general order of the admiralty, is owing. The effect of this wise measure (taken, of course, in conjunction with the general causes of improved health,) may be estimated from the following facts:—In 1780, the number of cases of scurvy received into Haslar hospital was 1457; in 1806 one only, and in 1807 one. There are now many surgeons in the navy who have never seen the disease.

15Throughout France the conductor is recognised as a most valuable and useful instrument; and in those parts of Germany where thunder-storms are still more common and tremendous they are become nearly universal. In Munich there is hardly a modern house unprovided with them, and of a much better construction than ours—several copper wires twisted into a rope.

16We have been informed by an eminent physician in Rome, (Dr. Morichini) that a vast quantity of the sulphate of quinine is manufactured there and consumed in the Campagna, with an evident effect in mitigating the severity of the malarious complaints which affect its inhabitants.

17Dr. Johnson, Memoirs of the Medical Society, vol. v.

18The engine at Huel Towan. See Mr. Henwood’s Statement “of the performance of steam-engines in Cornwall for April, May, and June, 1829.” Brewster’s Journal, Oct. 1829.—The highest monthly average of this engine extends to 79 millions of pounds.

19However, this is not quite a fair statement; a man’s daily labour is about 4 lbs. of coals. The extreme toil of this ascent arises from other obvious causes than the mere height.

20Its surface is about 40,000 acres, and medium depth about 20 feet. It was proposed to drain it by running embankments across it, and thus cutting it up into more manageable portions to be drained by windmills.

21No one doubts the practicability of the undertaking. Eight or nine thousand chaldrons of coals duly burnt would evacuate the whole contents. But many doubt whether it would be profitable, and some, considering that a few hundreds of fishermen who gain their livelihood on its waters would be dispossessed, deny that it would be desirable.

22“Experiments to determine the Force of fired Gunpowder.” Phil. Trans. vol. lxxxvii. p. 254. et seq.

23See a very ingenious application of this kind in Mr. Babbage’s article on Diving in the Encyc. Metrop.—Others will readily suggest themselves. For instance, the ballast in reserve of a balloon might consist of materials capable of evolving great quantities of hydrogen gas in proportion to their weight, should such be found.

24The sulphuric. Bracconot, Annales de Chimie, vol. xii. p. 184.

25D’Arcet, Annales de l’Industrie, Fevrier, 1829.

26See Dr. Prout’s account of the experiments of professor Autenrieth of Tubingen. Phil. Trans. 1827, p. 381. This discovery, which renders famine next to impossible, deserves a higher degree of celebrity than it has obtained.

27Greenwich.

28Maskelyne’s.

29Thomson’s First Principles of Chemistry, vol. ii. p. 68.

30Galileo exposes unsparingly the Aristotelian style of reasoning. The reader may take the following from him as a specimen of its quality. The object is to prove the immutability and incorruptibility of the heavens; and thus it is done:—

I. Mutation is either generation or corruption.

II. Generation and corruption only happen between contraries.

III. The motions of contraries are contrary.

IV. The celestial motions are circular.

V. Circular motions have no contraries.

a. Because there can be but three simple motions.

1. To a centre.
2. Round a centre.
3. From a centre.

. Of three things, one only can be contrary to one.

?. But a motion to a centre is manifestly the contrary to a motion from a centre.

d. Therefore a motion round a centre (i.e. a circular motion) remains without a contrary.

VI. Therefore celestial motions have no contraries—therefore among celestial things there are no contraries—therefore the heavens are eternal, immutable, incorruptible, and so forth.

It is evident that all this string of nonsense depends on the excessive vagueness of the notions of generation, corruption, contrariety, &c. on which the changes are rung.—See Galileo, Systema Cosmicum, Dial. i. p. 30.

31Macquer justly observes, that the alchemists would have rendered essential service to chemistry had they only related their unsuccessful experiments as clearly as they have obscurely related those which they pretend to have been successful.—Macquer’s Dictionary of Chemistry, i. x.

32Paracelsus performed most of these cures by mercury and opium, the use of which latter drug he had learned in Turkey. Of mercurial preparations the physicians of his time were ignorant, and of opium they were afraid, as being “cold in the fourth degree.” Tartar was likewise a great favourite of Paracelsus, who imposed on it that name, “because it contains the water, the salt, the oil, and the acid, which burn the patient as hell does:” in short, a kind of counterbalance to his opium.

33See the Life of Galileo Galilei, by Mr. Drinkwater, with Illustrations of the Advancement of Experimental Philosophy.

34The temporary star in Cassiopeia observed by Cornelius Gemma, in 1572, was so bright as to be seen at noon-day. That in Serpentarius, first seen by Kepler in 1604, exceeded in brilliancy all the other stars and planets.

35Edinburgh Phil. Journ. 1819, vol. i. p. 8.

36The abstract principle of repetition in matters of measurement (viz. juxta-position of units without error) is applicable to a great variety of cases in which quantities are required to be determined to minute nicety. In chemistry, in determining the standard atomic weights of bodies, it seems easily and completely applicable, by a process which will suggest itself at once to every chemist, and seems the only thing wanting to place the exactness of chemical determinations on a par with astronomical measurements.

37Accurate and perfectly authentic copies of the yard and pound, executed in platina, and hermetically sealed in glass, should be deposited deep in the interior of the massive stone-work of some great public building, whence they could only be rescued with a degree of difficulty sufficient to preclude their being disturbed unless on some very high and urgent occasion. The fact should be publicly recorded, and its memory preserved by an inscription. Indeed, how much valuable and useful information of the actual existing state of arts and knowledge at any period might be transmitted to posterity in a distinct, tangible, and imperishable form, if, instead of the absurd and useless deposition of a few coins and medals under the foundations of buildings, specimens of ingenious implements or condensed statements of scientific truths, or processes in arts and manufactures, were substituted. Will books infallibly preserve to a remote posterity all that we may desire should be hereafter known of ourselves and our discoveries, or all that posterity would wish to know? and may not a useless ceremony be thus transformed into an act of enrolment in a perpetual archive of what we most prize, and acknowledge to be most valuable?

38In the system alluded to, the name of quartz is assigned to iolite and obsidian; that of mica to plumbago, chlorite, and uranite; sulphur, to orpiment and realgar, &c. See Mohs’s System of Mineralogy, translated by Haidinger.

39The following passage, from Lindley’s Synopsis of the British Flora, characterises justly the respective merits, in a philosophical point of view, of natural and artificial systems of classification in general, though limited in its expression to his own immediate science:—“After all that has been effected, or is likely to be accomplished hereafter, there will always be more difficulty in acquiring a knowledge of the natural system of botany than of the LinnÆan. The latter skims only the surface of things, and leaves the student in the fancied possession of a sort of information which it is easy enough to obtain, but which is of little value when acquired: the former requires a minute investigation of every part and every property known to exist in plants; but when understood has conveyed to the mind a store of real information, of the utmost use to man in every station of life. Whatever the difficulties may be of becoming acquainted with plants according to this method, they are inseparable from botany, which cannot be usefully studied without encountering them.” Schiller has some beautiful lines on this, entitled “Menschliches Wissen” (or Human Knowledge); Gedichte, vol. i. p. 72. Leipzig, 1800.

40Lyell’s Principles of Geology, vol. i. Fourrier, MÉm. de l’Acad. des Sciences, tom. vii. p. 592. “L’Établissement et le progrÈs des sociÉtÉs humaines, l’action des forces naturelles, peuvent changer notablement, et dans de vastes contrÉes, l’État de la surface du sol, la distribution des eaux, et les grands mouvemens de l’air. De tels effets sont propres À faire varier, dans le cours de plusieurs siÈcles, le dÉgrÉ de la chaleur moyenne; car les expressions analytiques comprennent des coefficiens qui se rapportent À l’État superficiel, et qui influent beaucoup sur la valeur de la tempÉrature.” In this enumeration, by M. Fourrier, of causes which may vary the general relation of the surface of extensive continents to heat, it is but justice to Mr. Lyell to observe, that the gradual shifting of the places of the continents themselves on the surface of the globe, by the abrading action of the sea on the one hand, and the elevating agency of subterranean forces on the other, does not expressly occur and cannot be fairly included in the general sense of the passage, which confines itself to the consideration of such changes as may take place on the existing surface of the land.

41The reader will find this subject further developed in a paper lately communicated to the Geological Society.

42Phil. Trans. 1824.

43Wells on Dew.

44Principia, book iii. prop. 6.

45A very curious instance of the pursuit of a law completely empirical into an extreme case is to be found in Newton’s rule for the dilatation of his coloured rings seen between glasses at great obliquities. Optics, book ii. part i. obs. 7.

46See Phil. Trans. 1819.

47“When we are told that Saturn moves in his orbit more than 22,000 miles an hour, we fancy the motion to be swift; but when we find that he is more than three hours moving his own diameter, we must then think it, as it really is, slow.” Thirty Letters on various Subjects, by William Jackson, 1795.

48Thomson’s First Principles of Chemistry.

49There seems no doubt, however, that an achromatic telescope had been constructed by a private amateur, a Mr. Hall, some time before either Euler or Dollond ever thought of it.

50We allude to the recently invented achromatic combinations of Messrs. Barlow and Rogers, and the dense glasses of which Mr. Faraday has recently explained the manufacture in a memoir full of the most beautiful examples of delicate and successful chemical manipulation, and which promise to give rise to a new era in optical practice, by which the next generation at least may benefit. See Phil. Trans. 1830.

51Alphonso of Castile, 1252.

52Jackson, Letters on Various Subjects, &c.

53Thomson’s First Principles of Chemistry, Introduction.

54The progress of astronomical discovery has since shown that this law cannot be relied on (1851).

55Novum Organum, part ii. table 2. (24), (30), &c. on the form or nature of heat.

56We will mention one which we do not remember to have seen noticed elsewhere in the case of a disturbance of the equilibrium of heat produced by means purely mechanical, and by a process depending entirely on a certain order and sequence of events, and the operation of known causes. Suppose a quantity of air enclosed in a metallic reservoir, of some good conductor of heat, and suddenly compressed by a piston. After giving time for the heat developed by the condensation to be communicated from the air to the metal which will be thereby more or less raised in temperature above the surrounding atmosphere, let the piston be suddenly retracted and the air restored to its original volume in an instant. The whole apparatus is now precisely in its initial situation, as to the disposition of its material parts, and the whole quantity of heat it contains remains unchanged. But it is evident that the distribution of this heat within it is now very different from what it was before; for the air in its sudden expansion cannot re-absorb in an instant of time all the heat it had parted with to the metal: it will, therefore, have a temperature below that of the general atmosphere, while the metal yet retains one above it. Thus, a subversion of the equilibrium of temperature has been bon fide effected. Heat has been driven from the air into the metal, while every thing else remains unchanged.

We have here a means by which, it is evident, heat may be obtained, to any extent, from the air, without fuel. For if, in place of withdrawing the piston and letting the same air expand, within the reservoir, it be allowed to escape so suddenly as not to re-absorb the heat given off, and fresh air be then admitted and the process repeated, any quantity of air may thus be drained of its heat.

57See Phil. Trans. 1824.

58If the brain be an electric pile, constantly in action, it may be conceived to discharge itself at regular intervals, when the tension of the electricity developed reaches a certain point, along the nerves which communicate with the heart, and thus to excite the pulsations of that organ. This idea is forcibly suggested by a view of that elegant apparatus, the dry pile of Deluc; in which the successive accumulations of electricity are carried off by a suspended ball, which is kept by the discharges in a state of regular pulsation for any length of time. We have witnessed the action of such a pile maintained in this way for whole years in the study of the above-named eminent philosopher. The same idea of the cause of the pulsation of the heart appears to have occurred to Dr. Arnott; and is mentioned in his useful and excellent work on physics, to which however, we are not indebted for the suggestion, it having occurred to us independently many years ago.

59See a description of a contrivance of this kind by Dr. Young, Lectures, vol. i. p. 191.

60Boyle’s Works, folio, vol. iii. Essay x. p. 185.

61Jackson, The Four Ages, p. 52. London: Cadell and Davies, 1798. 8vo.

62Jackson, The Four Ages, p. 90.