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its fuliginous atoms, nor that which causeth the flame properly to be termed air, but rather, as he expresseth it, the accension of fuliginous exhalations, which contain an unctuosity in them, and arise from the matter of fuel'; which opinion will salve many doubts, whereof the common conceit affordeth no solution.

As first, how fire is stricken out of flints? that is, not by kindling the air from the collision of two hard bodies; for then diamonds should do the like better than flints; but rather from sulphureous, inflamed, and even vitrified effluviums and particles, as hath been observed of late. The like, saith Jordan, we observe in canes, and woods that are unctuous and full of oil, which will yield fire by frication or collision, not by kindling the air about them, but the inflammable oil within them. Why the fire goes out without air? that is, because the fuliginous exhalations, wanting evaporation, recoil upon the flame and choke it, as is evident in cupping-glasses, and the artifice of charcoals, where, if the air be altogether excluded, the fire goes out. Why some lamps included in close bodies have burned many hundred years, as that discovered in the sepulchre of Tullia, the sister of Cicero, and that of Olibius many years after, near Padua? because, what ever was their matter, either a preparation of gold or naptha, the duration proceeded from the purity of their oil, which yielded no fuliginous exhalations to suffocate the fire; for if air had nourished the flame, it had not continued many minutes, for it would have been spent and

sulphureous.] Itt is manifest to sense, that in the collision of the steele and the flint there is a sulphureous odour, which thoughe but fainte (in regard of the small splinters from whence it comes) yet to an acute and unobstructed braine is plainly perceptible.-Wr. See note at page 102.

saith Jordan, &c.] Dr. Jordan's observation appears to have been an anticipation of Sir H. Davy's, who having been informed that two pieces of bonnet cane rubbed together produced a faint light, examined the phænomenon, and found that all canes of this kind "when briskly rubbed together, produced sparks of white light. The luminous appearance was much more vivid on collision. When the canes were violently struck together, sparks nearly as vivid as those from the gunlock were produced." The cause he ascertained to be that the epidermis of the cane was composed chiefly of silica.-Br.

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fire.] And with the fire a smel as of oylye substance fired.- Wr.

wasted by the fire.? Why a piece of flax will kindle, although it touch not the flame ? because the fire extendeth further than indeed it is visible, being at some distance from the wick, a pellucid and transparent body, and thinner than the air itself. Why metals, in their liquation, although they intensely heat the air above their surface, arise not yet into a flame, nor kindle the air about them? because their sulphur is more fixed, and they emit not inflammable exhalations. And lastly, why a lamp or candle burneth only in the air about it, and inflameth not the air at a distance from it? because the flame extendeth not beyond the inflammable effluence, but closely adheres unto the original of its inflammation; and therefore it only warmeth, not kindleth the air about it. Which notwithstanding it will do, if the ambient air be impregnate with subtle inflammabilities, and such as are of quick accension, as experiment is made in a close room, upon an evaporation of spirits of wine and camphor; as subterraneous fires do sometimes happen,8 and as Creusa and Alexander's boy in the bath were set on fire by naptha.

7 Why some lamps, &c.] For a curious discussion on these marvellous lamps, see Ozanam's Philosophical Recreations, by Hutton, vol. i. p. 496. 8 as subterraneous fires do sometimes happen.] This remark, and indeed the whole of Browne's enquiries and observations in the two preceding paragraphs, respecting the nature of flame, very naturally remind us of one of the most splendid (because most useful) achievements of modern science-Sir Humphrey Davy's invention of the safety-lamp, for the purpose of obviating those "subterraneous" explosions which had previously occurred with destructive frequency, in the working of our collieries.

The causes and character of these terrific explosions, the means used in the early part of the present century to induce the efforts of scientific men to discover a remedy, and the perfect success which attended those of Sir Humphrey for that purpose, form the subject of a detailed and most interesting narrative in the 11th chapter of Dr. Paris's Life of Sir H. Davy.

The carburetted hydrogen given out by coal, and found frequently in vast masses in the crevices, or fissures, which are opened in working the mines, forms by combination with atmospheric air that inflammable gas, technically called fire-damp. The manner in which this gas explodes, is thus graphically described by Dr. Paris :-"On the approach of a candle, it is in an instant kindled: the expanding fluid drives before it a roaring whirlwind of flaming air, which tears up every thing in its progress, scorching some of the miners to a cinder, and burying others. under enormous ruins shaken from the roof; when thundering to the

Lastly, the element of air is so far from nourishing the body, that some have questioned the power of water; many

shafts, it converts the mine, as it were, into an enormous piece of artillery, and wastes its fury in a discharge of thick clouds of coal-dust,. stones, and timber, together with the limbs and mangled bodies of men and horses."-Vol. ii. p. 63.

A society was established on the 1st of October, 1813, at BishopWearmouth, by Sir Ralph Milbanke, Dr. Gray (afterwards Bishop of Bristol), and other gentlemen, "for preventing accidents in coalmines," which obtained the patronage of the Bishop of Durham, the Duke of Northumberland, and other noblemen and gentlemen. This society established a correspondence with others, and at length, through the chairman, Dr. Gray, engaged Sir Humphrey Davy in the investigation. He soon ascertained, by experiment on fire-damp, that it is a combination of hydrogen and carbon: that it will not explode if mixed with less than six times, nor more than fourteen times its volume of atmospheric air;-that an explosive mixture of gas, admitted into a vessel having apertures only above and below, merely enlarges the light, and then gradually extinguishes it without explosion--that the explosive gas will not explode in a tube less than one-eighth of an inch in diameter: -and that red hot charcoal does not explode, but gives light in the explosive gas. On these principles various lamps were constructed by Sir Humphrey, which were perfectly safe; but their light was extinguished when the air became so polluted with fire-damp as to be explosive. It remained then for him (as Dr. Paris observes), after having disarmed the fire-damp of its terror, to enlist it into his service.-"The simple means by which this was effected are as interesting as their results are important. He had previously arrived at the fact, that wire-gauze might be substituted as air-feeders to the lamp, in the place of his tubes or safety canals: but not until the lapse of several weeks, did the happy idea of constructing the lamp entirely of wire gauze occur to him :-the history of this elaborate enquiry affords a striking proof of the inability of the human mind to apprehend simplicities, without a process of complication, which works as the grappling machinery of truth. His original lamp, with tubes or canals, as already described, was perfectly safe in the most explosive atmosphere, but its light was necessarily extinguished by it; whereas in the wire-gauze. cage, the fire-damp itself continues to burn, and thus to afford to the miner a useful light, while he is equally secured from the fatal effects of explosion.

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Nothing now remained but to ascertain the degree of fineness which the wire-gauze ought to possess in order to form a secure barrier against the passage of flame. For this purpose, Davy placed his lighted lamps in a glass receiver, through which there was a current of air which passed into the lamp more or less explosive, and caused it to change rapidly or slowly at pleasure, so as to produce all possible varieties of inflammable and explosive mixtures: and he found that iron wire-gauze, composed of wires from one fortieth to one sixtieth of an inch in diameter, and

conceiving it enters not the body in the power of aliment, or that from thence there proceeds a substantial supply. For beside that some creatures drink not at all; even unto ourselves, and more perfect animals, though many ways assistant thereto, it performs no subtantial nutrition, serving for refrigeration, dilution of solid aliment, and its elixation in the stomach; which from thence, as a vehicle, it conveys through less accessible cavities, and so in a rorid substance through the capillary cavities, into every part; which having performed, it is afterward excluded by urine, sweat, and serous separations. And this opinion surely possessed the ancients; for when they so highly commended that water which is suddenly hot and cold, which is without all savour, the lightest, the thinnest, and which will soonest boil beans or peas, they had no consideration of nutrition; whereunto had they had respect, they would have surely commended gross and turbid streams, in whose confusion at least, there might be contained some nutriment; and not jejune or limpid water, nearer the simplicity of its element. Although, I confess, our clearest waters, and such as seem simple unto sense, are much compounded unto reason, as may be observed in the evaporation of large quantities of water, wherein beside a terreous residence, some salt is also found, as is also observable in rain water; which appearing pure and empty, is full of seminal principles, and carrieth vital atoms of plants and animals in

containing twenty-eight wires, or seven hundred and eighty-four apertures to the inch, was safe under all circumstances, in atmospheres of this kind and he consequently employed that material in guarding lamps for the coal-mines, where, in January, 1816, they were immediately adopted, and have long been in general use."-Vol. ii. pp. 97-9.

Such is a rapid and very slight sketch of the history of a discovery which (to use Dr. P.'s words), "whether considered in relation to its scientific importance, or to its great practical value, must be regarded as one of the most splendid triumphs of human genius. It was the fruit of elaborate experiment and close induction: chance, or accident, which comes in for so large a share of the credit of human invention, has no claim to prefer upon this occasion: step by step may he be followed throughout the whole progress of his research, and so obviously does the discovery of each new fact spring from those that preceded it, that we never for a moment lose sight of our philosopher, but keep pace with him during the whole of his enquiry."

9 elixation.] Boiling or stewing.

1 nutrition.] But only of puritye for refreshing the harte.— Wr.

it, which have not perished in the great circulation of nature; as may be discovered from several insects generated in rain water from the prevalent fructification of plants thereby; and (beside the real plant of Cornerius*) from vegetable figurations, upon the sides of glasses, so rarely delineated in frosts.2

All which considered, severer heads will be apt enough to conceive the opinion of this animal, not much unlike that of the astomi, or men without mouths, in Pliny; suitable unto the relation of the mares in Spain, and their subventaneous conceptions from the western wind; and in some way more unreasonable than the figment of Rabican, the famous horse in Ariosto, which being conceived by flame and wind, never tasted grass, or fed on any grosser provender than air; for this way of nutrition was answerable unto the principles of his generation. Which being not airy, but gross and seminal in the chameleon, unto its conservation there is required a solid pasture, and a food congenerous unto the principles of its nature.

The grounds of this opinion are many: the first observed by Theophrastus, was the inflation or swelling of the body made in this animal upon inspiration or drawing in its breath: which people observing, have thought it to feed upon air. But this effect is rather occasioned upon the greatness of its lungs, which in this animal are very large, and by their backward situation afford a more observable dilatation; and though their lungs be less, the like inflation is observable in toads, but especially in sentortoises.3

A second is the continual hiation or holding open its mouth, which men observing, conceive the intention thereof to receive the aliment of air; but this is also occasioned by the greatness of its lungs; for repletion whereof, not having a sufficient or ready supply by its nostrils, it is enforced to dilate and hold open the jaws.

The third is the paucity of blood observed in this animal, scarce at all to be found but in the eye, and about the heart ;

* Zibavius, tom. iv. Chym.

2 Although, I confess, &c.] This sentence was first added in 2nd edition.

3 but especially in sentortoises.] These gentry were first mentioned in the 6th edition.

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