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. [Sidenote: _How to make Ice at any time of the year._]