rt> A HISTORY OF 



wifn a loud noise, and blew up the cover of the box wherein it lay 

 Such is its force in an ordinary experiment. But it has been knowr 

 lo burst cannons, filled with water, and then left to freeze ; for the 

 cold congealing the water, and the ice swelling, it became irresistible. 

 The bursting of rocks, by frost, which is frequent in the northern cli- 

 mates, and is sometimes seen in our own, is an equal proof of the ex 

 pansion of congealed water. For having by some means insinuated 

 itself into the body of the rock, it has remained there till the cold was 

 sufficient to afl'ect it by congelation. But when once frozen, no ob- 

 stacle is able to confine it from dilating; and, if it cannot otherwise 

 find room, the rock must burst asunder. 



This alteration in the bulk of water might have served as a proof that 

 it was capable of being compressed into a narrower space than it oc- 

 cupied before ; but, till of late, water was held to be incompressible. 

 The general opinion was, that no art whatsoever could squeeze it intc 

 a narrower compass; that no power on earth, for instance, could 

 force a pint of water into a vessel that held a hair's-breadth less than 

 a pint. And this, said they, appears from the famous Florentine ex- 

 periment ; where the water, rather than suffer compressure, was seen 

 to ooze through the pores of the solid metal ; and, at length, making 

 a cleft in the side, spur ~ut with great vehemence. But later trials 

 have proved that water is very compressible, and partakes of that 

 elasticity which every other body possesses in some degree. In- 

 deed, had not mankind been dazzled by the brilliancy of one incon- 

 clusive experiment, there were numerous reasonstoconvince them of 

 its having the same properties with other substances. Ic, which is 

 water in another state, is very elastic. A stone, flung slantingly 

 along the surface of a pond, bounds from the water several times ; 

 which shows it to be elastic also. But the trials of Mr. Canton have 

 put this past all doubt ; which being somewhat similar to those of the 

 great Boyle, who pressed it with weights properly applied, carry suf 

 ficient conviction. 



What has been hitherto related, is chiefly applicable to the element 

 of water alone ; but its fluidity is a property that it possesses in com- 

 mon with several other substances, in other respects greatly differing 

 from it. That quality which gives rise to the definition of a fluid, 

 namely, that its parts are in a continual intestine motion, seems ex- 

 tremely applicable to water. What the shapes of those parts are, it 

 would be vain to attempt to discover. Every trial only shows the fu- 

 tility of the attempt; all we find is, that they are extremely minute; 

 and that they roll over each other with the greatest ease. Some, in- 

 deed, from this property alone, have not hesitated to pronounce them 

 globular ; and we have, in all our hydrostatical books, pictures of 

 these little globes in a state of sliding and rolling over each other. 

 But all this is merely the work of imagination ; we know that sub- 

 stances of any kind, reduced very small, assume a fluid appearance, 

 somewhat resembling that of water. Mr. Boyle, after finely powder, 

 ing and sifting a little dry powder of Plaster of Paris, put it in a ves- 

 sel over the fire, where it soon began to boil like water, exhibiting all the 

 motions and appearances of a boiling liquor. Although but a povvdei, 

 the parts of which we know are vory different from erch < th*r, and 



