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

28. Of Thawing or dissolving of Frozen bodies.

AS Freezing or Congelation is caused by con∣tracting, condensing, and retentive Motions; so Thawing is nothing else, but dissolving, dilating, and Page  120 extending motions; for Freezing and Thawing are two contrary actions; and as Freezing is caused several ways, according to the various disposition of congela∣ble bodies, and the temper of exterior cold; so Thaw∣ing, or a dissolution of frozen bodies, may be occasi∣oned either by a sympathetical agreement; as for ex∣ample, the thawing of Ice in water, or other liquors, or by some exterior imitation, as by hot dilating moti∣ons. And it is to be observed, That as the time of freezing, so the time of dissolving is according to the several natures and tempers both of the frozen bodies themselves, and the exterior objects applied to frozen bodies, which occasion their thawing or dissolution: for it is not onely heat that doth cause Ice, or Snow, or other frozen bodies to melt quicker or slower, but ac∣cording as the nature of the heat is, either more or less dilative, or more or less rarifying; for surely an exte∣rior actual heat is more rarifying then an interior vir∣tual heat; as we see in strong spirituous liquors which are interiously contracting, but being made actually hot, become exteriously dilating: The like of many other bodies; so that actual heat is more dissolving then vir∣tual heat. And this is the reason why Ice and Snow will melt sooner in some Countries or places then in others, and is much harder in some then in others; for we see that neither Air, Water, Earth, Mi∣nerals, nor any other sorts of Creatures are just a∣like in all Countries or Climates: The same may be Page  121 said of heat and cold. Besides, it is to be observed, that oftentimes a different application of one and the same object will occasion different effects; as for example, if Salt be mixed with Ice, it may cause the contracted body of Ice to change its present motions into its for∣mer state or figure, viz. into water; but being applied outwardly, or on the out-side of the Vessel wherein Snow or Ice is contained, it may make it freeze harder, instead of dissolving it. Also Ice will oftentimes break into pieces of its own accord, and without the applica∣tion of any exterior object; and the reason, in my opinion, is, that some of the interior parts of the Ice, en∣deavouring to return to their proper and natural figure by vertue of their interior dilative motions, do break and divide some of the exterior parts that are contracted by the motions of Frost, especially those which have not so great a force or power as to resist them.

But concerning Thawing, some by their trails have found, that if frozen Eggs, Apples, and the like bodies, be thawed near the fire, they will be thereby spoiled; but if they be immersed in cold water, or wrapt into Ice or Snow, the internal cold will be drawn out, as they suppose, by the external; and the frozen bo∣dies will be harmlesly, though not so quickly thawed. And truly this experiment stands much to reason; for, in my opinion, when frozen bodies perceive heat or fire, the motions of their frozen parts upon the percep∣tion, endeavour to imitate the motions of heat or fire, Page  122 which being opposite to the motions of cold, in this sudden and hasty change, they become irregular in so much as to cause in most frozen parts a dissolution of their interior natural figure; Wherefore it is very probable, that frozen bodies will thaw more regularly in water, or being wrapt into Ice or Snow, then by heat or fire; for Thawing is a dilating action, and Water, as also Ice and Snow (which are nothing but congealed water) being of a dilative nature, may ea∣sily occasion a thawing of the mentioned frozen parts by Sympathy, provided, the Motions of the exterior cold do not over-power the motions of the interior fro∣zen parts; for if a frozen body should be wrapt thus in∣to Ice or Snow, and continue in an open, cold frosty air, I question whether it would cause a thaw in the same body, it would preserve the body in its frozen state from dissolving or disuniting, rather then occasion its thawing. But that such frozen bodies, as Apples, and Eggs, &c. immersed in water, will produce Ice on their out-sides, is no wonder, by reason the motions of Water imitate the motions of the frozen bodies; and those parts of water that are nearest, are the first imitators, and become of the same mode. By which we may see, that some parts will cloath themselves, others onely vail themselves with artificial dresses, most of which dresses are but copies of other motions, and not original acti∣ons; It makes also evident, that those effects are not caused by an ingress of frigorifick atomes in water, or Page  123 other congelable bodies, but by the perceptive moti∣ons of their own parts. And what I have said of Cold, the same may be spoken of heat; for it is known, that a part of a mans body being burned with fire, the burning may be cured by the heat of the fire; which, in my opinion, proceeds from a sympathetical agreement be∣twixt the motions of the fire, and the motions of the burned part; for every part of a mans body hath its na∣tural heat, which is of an intermediate temper; which heat being heightened by the burning motions of fire beyond its natural degree, causes a burning and smart∣ing pain in the same part; and therefore as the fire did occasion an immoderate heat, by an intermixture of its own parts with the parts of the flesh; so a moderate heat of the fire may reduce again the natural heat of the same parts, and that by a sympathetical agreement betwixt the motions of the Elemental and Animal heat; But it is to be observed, first, that the burning must be done by an intermixture of the fire with the parts of the body: Next, that the burning must be but skin deep (as we use to call it) that is, the burned part must not be totally overcome by fire, or else it will never be re∣stored again. Neither are all burned bodies restored after this manner, but some; for one and the same thing will not in all bodies occasion the like effects; as we may see by Fire, which being one and the same, will not cause all fuels to burn alike; and this makes true the old saying, One Mans Meat is another Mans Poyson. The truth Page  124 is, it cannot be otherwise; for though Nature, and natural self-moving Matter is but one body, and the onely cause of all natural effects; yet Nature being divided into infinite, corporeal, figurative self-moving parts, these parts, as the effects of that onely cause, must needs be various; and again, proceeding from one infinite cause, as one matter, they are all but one thing, because they are infinite parts of one Infinite body. But some may say, If Nature be but one body, and the Infinite parts are all united into that same body; How comes it that there is such an opposition, strife, and war betwixt the parts of Nature? I answer: Nature be∣ing Material, is composeable and divideable; and as Composition is made by a mutual agreement of parts, so division is made by an opposition or strife betwixt parts; which opposition or division doth not obstruct the Union of Nature, but, on the contrary, rather proves, that without an opposition of parts, there could not be a union or composition of so many several parts and creatures, nor no change or variety in Nature; for if all the parts did unanimously conspire and agree in their motions, and move all but one way, there would be but one act or kind of motion in Nature; when as an opposition of some parts, and a mutual agree∣ment of others, is not onely the cause of the Mira∣culous variety in Nature, but it poyses and bal∣lances, as it were, the corporeal, figurative motions, which is the cause that Nature is steady and fixt in Page  125 her self, although her parts be in a perpetual mo∣tion.