The Works of Sir Thomas Browne, Volume 1

by Sir Thomas Browne

Now besides Authority against it, there may be many reasons deduced from their several differences which seem to overthrow it. And first, a difference is probable in their concretion. For if Crystal be a stone (as in the number thereof it is confessedly received,) it is not immediately concreted by the efficacy of cold, but rather by a Mineral spirit, and lapidifical principles of its own, and therefore while it lay in solutis principiis, and remained in a fluid Body, it was a subject very unapt for proper conglaciation; for Mineral spirits do generally resist and scarce submit thereto. So we observe that many waters and springs will never freeze, and many parts in Rivers and Lakes, where there are Mineral eruptions, will still persist without congelations, as we also observe in Aqua fortis, or any Mineral solution, either of Vitriol, Alum, Salt-petre, Ammoniac, or Tartar, which although to some degree exhaled, and placed in cold Conservatories, will Crystallize and shoot into white and glacious bodies; yet is not this a congelation primarily effected by cold, but an intrinsecal induration from themselves; and a retreat into their proper solidities, which were absorbed by the liquor, and lost in a full imbibition thereof before. And so also when wood and many other bodies do putrifie, either by the Sea, other waters, or earths abounding in such spirits; we do not usually ascribe their induration to cold, but rather unto salinous spirits, concretive juices, and causes circumjacent, which do assimilate all bodies not indisposed for their impressions.

But Ice is water congealed by the frigidity of the air, whereby it acquireth no new form, but rather a consistence or determination of its diffluency, and amitteth not its essence, but condition of fluidity. Neither doth there any thing properly conglaciate but water, or watery humidity; for the determination of quick-silver is properly fixation, that of milk coagulation, and that of oyl and unctious bodies, only incrassation; And therefore Aristotle makes a trial of the fertility of humane seed, from the experiment of congelation; for that (saith he) which is not watery and improlifical will not conglaciate; which perhaps must not be taken strictly, but in the germ and spirited particles: For Eggs I observe will freeze, in the albuginous part thereof. And upon this ground Paracelsus in his Archidoxis, extracteth the magistery of wine; after four moneths digestion in horse-dung, exposing it unto the extremity of cold; whereby the aqueous parts will freeze, but the Spirit retire and be found congealed in the Center.

How to make Ice at any time of the year.

But whether this congelation be simply made by cold, or also by co-operation of any nitrous coagulum, or spirit of Salt the principle of concretion; whereby we observe that ice may be made with Salt and Snow by the fire side; as is also observable from Ice made by Saltpetre and water, duly mixed and strongly agitated at any time of the year, were a very considerable enquiry. For thereby we might clear the generation of Snow, Hail, and hoary Frosts, the piercing qualities of some winds, the coldness of Caverns, and some Cells. We might more sensibly conceive how Salt-petre fixeth the flying spirits of Minerals in Chymical Preparations, and how by this congealing quality it becomes an useful medicine in Fevers.

Again, The difference of their concretion is collectible from their dissolution; which being many ways performable in Ice, is few ways effected in Crystal. Now the causes of liquation are contrary to those of concretion; and as the Atoms and indivisible parcels are united, so are they in an opposite way disjoyned. That which is concreted by exsiccation or expression of humidity, will be resolved by humectation, as Earth, Dirt, and Clay; that which is coagulated by a fiery siccity, will suffer colliquation from an aqueous humidity, as Salt and Sugar, which are easily dissoluble in water, but not without difficulty in oyl, and well rectified spirits of Wine. That which is concreted by cold, will dissolve by a moist heat, if it consist of watery parts, as Gums, Arabick, Tragacanth, Ammoniac and others; in an airy heat or oyl, as all resinous bodies, Turpentine, Pitch, and Frankincense; in both, as gummy resinous bodies, Mastick, Camphire and Storax; in neither, as neutrals and bodies anomalous hereto, as Bdellium, Myrrhe, and others. Some by a violent dry heat, as Metals; which although corrodible by waters, yet will they not suffer a liquation from the powerfullest heat, communicable unto that element. Some will dissolve by this heat although their ingredients be earthy, as Glass, The original ingredients of Glass. whose materials are fine Sand, and the ashes of Chali or Fearn;and so will Salt run with fire, although it be concreted by heat. And this way may be effected a liquation in Crystal, but not without some difficulty; that is, calcination or reducing it by Art into a subtle powder; by which way and a vitreous commixture, Glasses are sometime made hereof, and it becomes the chiefest ground for artificial and factitious gemms. But the same way of solution is common also unto many Stones; and not onely Beryls and Cornelians, but Flints and Pebbles, are subject unto fusion, and will run like Glass in fire.

But Ice will dissolve in any way of heat, for it will dissolve with fire, it will colliquate in water, or warm oyl; nor doth it only submit unto an actual heat, but not endure the potential calidity of many waters. For it will presently dissolve in cold Aqua fortis, sp. of Vitriol, Salt, or Tartar, nor will it long continue its fixation in spirits of Wine, as may be observed in Ice injected therein.

Again, The concretion of Ice will not endure a dry attrition without liquation; for if it be rubbed long with a cloth, it melteth. But Crystal will calefie unto electricity, that is, a power to attract straws or light bodies, and convert the needle freely placed. Which is a declarement of very different parts, wherein we shall not inlarge, as having discoursed concerning such bodies in the Chap. of Electricks.

They are differenced by supernatation or floating upon water; for Crystal will sink in water, as carrying in its own bulk a greater ponderosity then the space in any water it doth occupy; and will therefore only swim in molten Metal and Quicksilver. But Ice will swim in water of what thinness soever; and though it sink in oyl, will float in spirits of Wine or Aqua vitæ. And therefore it may swim in water, not only as being water it self, and in its proper place, but perhaps as weighing somewhat less then the water it possesseth. And therefore as it will not sink unto the bottom, so will it neither float above like lighter bodies, but being near in weight, lie superficially or almost horizontally unto it. And therefore also an Ice or congelation of Salt or Sugar, although it descend not unto the bottom, yet will it abate, and decline below the surface in thin water, but very sensibly in spirits of Wine. For Ice although it seemeth as transparent and compact as Crystal, yet is it short in either; for its atoms are not concreted into continuity, which doth diminish its translucency; it is also full of spumes and bubbles, which may abate its gravity. And therefore waters frozen in Pans, and open Glasses, after their dissolution do commonly leave a froth and spume upon them, which are caused by the airy parts diffused in the congealable mixture which uniting themselves and finding no passage at the surface, do elevate the mass, and make the liquor take up a greater place then before: as may be observed in Glasses filled with water, which being frozen, will seem to swell above the brim. So that if in this condensation any one affirmeth there is also some rarefaction, experience may assert it.

They are distinguished in substance of parts and the accidents thereof, that is, in colour and figure; for Ice is a similary body, and homogeneous concretion, whose material is properly water, and but accidentally exceeding the simplicity of that element. But the body of Crystal is mixed; its ingredients many, and sensibly containeth those principles into which mixt bodies are reduced. For beside the spirit and mercurial principle it containeth a sulphur or inflamable part, and that in no small quantity; for besides its Electrick attraction, which is made by a sulphureous effluvium, it will strike fire upon percussion like many other stones, and upon collision with Steel actively send forth its sparks, not much inferiourly unto a flint. Now such bodies as strike fire have sulphureous or ignitible parts within them, and those strike best, which abound most in them. For these scintillations are not the accension of the air, upon the collision of two hard bodies, but rather the inflamable effluencies or vitrified sparks discharged from the bodies collided. For Diamonds, Marbles, Heliotropes and Agaths, though hard bodies, will not readily strike fire with a steel, much less with one another: Nor a Flint so readily with a Steel, if they both be very wet, for then the sparks are sometimes quenched in their eruption.