MADAM,
My discourse of Water in my last Letter has given you occasion to enquire after the reason, Why the weight of a great body of water doth not press so hard and heavily as to bruise or crush a body, when it is sunk down to the bottom? As for example: If a man should be drowned, and afterwards cast out from the bottom of a great Sea, or River, upon the shore; he would onely be found smother'd or choak'd to death, and not press'd, crush'd, or bruised, by the weight of water. I answer; The reasons are plain: for, first, the nature of a mans respiration requires such a temperature of breath to suck in, as is neither too thick, nor too thin for his lungs, and the rest of his interior parts, as also for the organs and passages of his exterior senses, but fit, proper, and proportionable to those mentioned parts of his body: As for example; in a too thin and rarified air, man will be as apt to die for want of breath, as in a too gross and thick air he is apt to die with a superfluity of the substance he imbreaths; for thick smoak, or thick vapour, as also too gross air, will soon smother a man to death; and as for choaking, if a man takes more into his throat then he can swallow, he will die; and if his stomack be filled with more food then it is able to digest, if it cannot discharge it self, he will die with the excess of food; and if there be no food, or too little put into it, he will also die for want of food. So the eye, if it receives too many, or too gross, or too bright objects, it will be dazled or blinded, and some objects through their purity are not to be seen at all: The same for Hearing, and the rest of the exterior senses: And this is the reason, why man, or some animal Creatures are smother'd and choak'd with water; because water is thicker then the grossest air or vapour; for if smoak, which is rarer then water, will smother and choak a man, well may water, being so much thicker. But yet this smothering or choaking doth not prove, that water hath an interior or innate density (as your Authors opinion is) no more then smoak, or thick and gross air hath; but the density of water is caused more through the wet and moist exterior parts, joyning and uniting closely together; and the interior nature of smoak being more moist or glutinous then thin air, and so more apt to unite its exterior parts, it makes it to come in effect nearer to water; for though water and smoak are both of rare natures, yet not so rare as clear and pure air; neither is water or smoak so porous as pure air, by reason the exterior parts of water and smoak are more moist or glutinous then pure air. But the thickness of water and smoak is the onely cause of the smothering of men, or some animals, as by stopping their breath, for a man can no more live without air, then he can without food; and a well tempered or middle degree of air is the most proper for animal Respiration; for if the air be too thick, it may soon smother or choak him; and if too thin, it is not sufficient to give him breath: And this is the reason that a man being drown'd, is not onely smother'd, but choak'd by water; because there enters more through the exterior passages into his body then can be digested; for water is apt to flow more forcibly and with greater strength then air; not that it is more dilating then air, but by reason it is thicker, and so stronger, or of more force; for the denser a body is, the stronger it is; and a heavy body, when moved, is more forcible then a light body. But I pray by this expression mistake not the nature of water; for the interior nature of water hath not that gravity, which heavy or dense bodies have, its nature being rare and light, as air, or fire; but the weight of water, as I said before, proceeds onely from the closeness and compactness of its exterior parts, not through a contraction in its interior nature; and there is no argument, which proves better, that water in its interior nature is dilating, then that its weight is not apt to press to a point; for though water is apt to descend, through the union of its parts, yet it cannot press hard, by reason of its dilating nature, which hinders that heavy pressing quality; for a dilating body cannot have a contracted weight, I mean, so as to press to a Center, which is to a point; and this is the reason, that when a grave or heavy body sinks down to the bottom of water, it is not opprest, hurt, crusht, or bruised by the weight of water; for, as I said, the nature of water being dilating, it can no more press hard to a center, then vapour, air, or fire: The truth is, water would be as apt to ascend as descend, if it were not for the wet, glutinous and sticking, cleaving quality of its exterior parts; but as the quantity and quality of the exterior parts makes water apt to sink, or descend, so the dilating nature makes it apt to flow, if no hinderance stop its course; also the quantity and quality of its exterior parts is the cause, that some heavy bodies do swim without sinking: as for example; a great heavy Ship will not readily sink, unless its weight be so contracted as to break asunder the united parts of water; for the wet quality of water causing its exterior parts to joyn close, gives it such an united strength, as to be able to bear a heavy burden, if the weight be dilated, or level, and not piercing or penetrating; for those bodies that are most compact, will sink sooner, although of less weight then those that are more dilated although of greater weight: Also the exterior and outward shape or form makes some bodies more apt to sink then others; Indeed, the outward form and shape of Creatures is one of the chief causes of either sinking or swimming. But to conclude, water in its interior nature is of a mean or middle degree, as neither too rare, nor too grave a body; and for its exterior quality, it is in as high a degree for wetness, as fire is for heat; and being apt both to divide, and to unite, it can bear a burden, and devour a burden, so that some bodies may swim, and others sink; and the cause, that a sunk body is not opprest, crush'd, or squeesed, is the dilating nature and quality of water, which hinders its parts from pressing or crowding towards a point or center; for although water is heavy, and apt to descend, yet its weight is not caused by a contraction of its substance, but by a union of its parts. Thus, Madam, I have obeyed your commands, in giving you my reasons to your propounded question, which if you approve, I have my aim; if not, I submit to your better judgment: for you know I am in all respects,
Madam,
Your Faithful Friend
to serve you.
[XIII.]
MADAM,
I am glad, you are pleased with my reasons I gave to your propounded question concerning the weight of Water; and since you have been pleased to send me some more of that subject, I shall be ready also to give my answer to them, according to the capacity of my judgment. First, you desire to know, How it comes, that Water will by degrees ascend through a narrow pipe, when the pipe is placed straight upright; or perpendicular? The reason, in my opinion is, that Water, having a dilative nature, when it finds an obstruction to descend or flow even, will dilate it self ascendingly, according as it hath liberty, or freedom, and strength, or quantity; the truth is, water would be more apt to ascend then to descend, were it not for the close uniting of its liquid Parts, which causes its exterior density, and this density makes it of more weight then its nature is; and the proof that water is apt in its nature to ascend, is, that some sorts of vapours are made onely by the dilation and rarefaction of ascending Water. Your second question is, Why the surface of water seems to be concave in its middle, and higher on every side? I answer, The interior figure of water is a circular figure, which being a round figure, is both concave, and convex; for where one is, the other must be; and the motions of ebbing and flowing, and ascending or descending, are partly of that figure; and so according to the exterior dilating strength or weakness, the exterior parts of water become either concave or convex; for in a full strength, as a full stream, the exterior parts of water flow in a convex figure, but when they want strength, they ebb in a concave figure. Your third question is, What makes frozen water apt to break those Vessels wherein it is contained, in the act of freezing or congealing? I answer: The same cause that makes water clear, as also more swell'd then usually it is: which cause is the inherent dilative nature of water; for water being naturally dilative, when as cold attractions do assault it, the moist dilations of water in the conflict use more then their ordinary strength to resist those cold contracting motions, by which the body of water dilates it self into a larger compass, according as it hath liberty or freedom, or quantity of parts; and the cold parts not being able to drive the water back to its natural compass, bind it as it is extended, like as if a beast should be bound when his legs and neck are thrust out at the largest extent, in striving to kick or thrust away his enemies and imprisoners: And so the reason why water breaks these vessels wherein it is inclosed, in the act of its freezing or congealing is, that when the cold contractions are so strong as they endeavour to extinguish the dilating nature of water, the water refilling, forces its parts so, as they break the vessel which incloses them: The same reason makes Ice clear and transparent; for it is not the rarefaction of water that doth it, but the dilation, which causes the parts of water to be not onely more loose and porous, but also more smooth and even, by resisting the cold contractions; for every part endeavours to defend their borders with a well ordered and regular flowing or streaming, and not onely to defend, but to enlarge their compass against their enemies. Your fourth question is, How it comes that Snow and Salt mixt together doth make Ice? The reason, in my judgment, is, that Salt being very active, and partly of the nature of fire, doth sometimes preserve, and sometimes destroy other bodies, according to its power, or rather according to the nature of those bodies it works on; and salt being mixt with snow, endeavours to destroy it; but having not so much force, melts it onely by its heat, and reduces it into its first principle, which is water, altering the figure of snow; but the cold contractions remaining in the water, and endeavouring to maintain and keep their power, straight draw the water or melted snow into the figure of ice, so as neither the salts heat, nor the waters dilative nature, are able to resist or destroy those cold contractions; for although they destroy'd the first figure, which is snow, yet they cannot hinder the second, which is Ice. Your last question is, How the Clouds can hang so long in the Skie without falling down? Truly, Madam, I do not perceive that Clouds, being come to their full weight and gravity, do keep up in the air, but some of them fall down in showres of rain, others in great and numerous flakes of snow; some are turned into wind, and some fall down in thick mists, so that they onely keep up so long, until they are of a full weight for descent, or till their figure is altered into some other body, as into air, wind, rain, lightning, thunder, snow, hail, mist, and the like. But many times their dilating motions keep or hinder them from descending, to which contracting motions are required. In my opinion, it is more to be admired, that the Sea doth not rise, then that Clouds do not fall; for, as we see, Clouds fall very often, as also change from being Clouds, to some other figure: Wherefore it is neither the Sun, nor Stars, nor the Vapours, which arise from the Earth, and cause the Clouds, nor the porosity of their bodies, nor the Air, that can keep or hinder them from falling or changing to some other body; but they being come to their full weight, fall or change according as is fittest for them. And these are all the reasons I can give you for the present; if they do not satisfie you, I will study for others, and in all occasions endeavour to express my self,
Madam,