Observations upon experimental philosophy to which is added The description of a new blazing world
Newcastle, Margaret Cavendish, Duchess of, 1624?-1674.

4. Of the Production of Fire by a Flint and Steel.

SOme learned Writers of Micrography, having observed the fiery sparks that are struck out by the violent motion of a Flint against Steel, suppose them to be little parcels either of the Flint or Steel, which by the violence of the stroke, are at the same time severed and made red hot; nay, sometimes to such a degree as they are melted together into glass. But whatsoever their opinion be, to my sense and reason it appears very dif∣ficult to determine exactly how the production of Fire is made, by reason there are so many different sorts of Productions in Nature, as it is impossible for any par∣ticular Creature to know or describe them: Never∣theless, it is most probable, that those two bodies do operate not by incorporeal but corporeal motions, Page  14 which either produce a third corporeal figure out of their own parts, or by striking against each other, do alter some of their natural corporeal figurative parts, so as to convert them into fire, which if it have no fuel to feed on, must of necessity die; or it may be, that by the occasion of striking against each other, some of their looser parts are metamorphosed, and afterwards return to their former figures again; like as flesh being bruised and hurt, becomes numb and black, and after returns again to its proper figure and colour; or like as Water that by change of motion in the same parts, turns into Snow, Ice, or Hail, may return again into its former figure and shape; for Nature is various in her corpo∣real figurative motions. But it is observable, that Fire is like seeds of Corn sown in Earth, which increases or decreases according as it has nourishment; by which we may see that Fire is not produced from a bare imma∣terial motion (as I said before;) for a spiritual issue cannot be nourished by a corporeal substance, but it is with Fire as it is with all, at least most other natural Creatures, which require Respiration as well as Per∣ception; for Fire requires Air as well as Animals do. By Respiration, I do not mean onely that animal respi∣ration which in Man, and other animal Creatures, is performed by the lungs, but a dividing and uniting, or separating and joyning of parts from and to parts, as of the exterior from and to the interior, and of the interior from and to the exterior; so that when some Page  15 parts issue, others do enter: And thus by the name of Respiration I understand a kind of Reception of for∣reign Matter, and emission of some of their own; as for example, in Animals, I mean not onely the respi∣ration performed by the lungs, but also the reception of food, and of other matter entering through some pro∣per organs and pores of their bodies, and the discharg∣ing of some other matter the sameway; and if this be so, as surely it is, then all or most Creatures in Nature have some kind of Respiration or Reciprocal breathing, that is, Attraction and Expiration, receiving of nou∣rishment and evacuation, or a reception of some for∣reign parts, and a discharging and venting of some of their own. But yet it is not necessary that all the mat∣ter of Respiration in all Creatures should be Air; for every sort of Creatures, nay every particular has such a matter of Respiration, as is proper both to the nature of its figure, and proper for each sort of respiration. Be∣sides, although Air may be a fit substance for Respi∣ration to Fire, and to some other Creatures, yet I can∣not believe, that the sole agitation of Air is the cause of Fire, no more then it can be called the cause of Man; for if this were so, then Houses that are made of Wood, or cover'd with Straw, would never fail to be set on fire by the agitation of the Air. Neither is it requisite that all Respirations in all Creatures should be either hot or cold, moist or dry, by reason there are many different sorts of Respiration, acording to the nature and pro∣priety Page  16 of every Creature, whereof some may be hot, some cold; some hot and dry, some cold and dry; some hot and moist, some cold and moist, &c. and in Animals, at least in Mankind, I observe, that the re∣spiration performed by the help of their lungs. is an attraction of some refrigerating air and an emission of some warm vapour. What other Creatures respi∣rations may be, I leave for others to inquire.