THE EARTH. 



51 



woulct take fire upon the application of a can- 

 dle." The whole body of the water then is 

 found replete with little worm-like insects, 

 that float, with great briskness, through all its 

 parts. These generally live for about a cou- 

 ple of days ; and then dying, by depositing 

 their spoils, for awhile increase the putrefac- 

 tion. After a time, the heavier parts of these 

 sinking to the bottom, the lighter float in a 

 scum, at the top ; and this is what mariners 

 call, the water's purging itself. There is still, 

 however, another race of insects, which are 

 bred, very probably, from the spoils of the 

 former ; and produce, after some time, similar 

 appearances : these dying, the water is then 

 thought to change no more. However, it ve- 

 ry often happens, especially in hot climates, 

 that nothing can drive these nauseous insects 

 from the ship's store of water. They often 

 increase to a very disagreeable and frightful 

 size, so as to deter the mariner, though parch- 

 ing with thirst, from tasting that cup which 

 they have contaminated. 



This water, as thus described, therefore, is 

 a very different fluid from that simple element- 

 ary substance upon which philosophical the- 

 ories have been founded ; and concerning the 

 nature of which there have been so many dis- 

 putes. Elementary water is no way com- 

 pounded ; but is without taste, smell, or 

 colour; and incapable of being discerned by 

 any of the senses, except the touch. This is 

 the famous dissolvent of the chymists, into 

 which, as they have boasted, they can reduce 

 all bodies; and which makes up all other 

 substances, only by putting on a different dis- 

 guise. In some forms, it is fluid, transparent, 

 and evasive of the touch; in others, hard, 

 firm, and elastic. In some, it is stiffened by 

 cold ; in others, dissolved by fire. Accord- 

 ing to them, it only assumes external shapes 

 from accidental causes ; but the mountain is 

 as much a body of water, as the cake of ice 

 that melts on its brow ; and even the philoso- 

 pher himself is composed of the same materi- 

 als with the cloud or meteor which he con- 

 templates. 



Speculation seldom rests when it begins. 

 Others, disallowing the universality of this 

 substance, will not allow that in a state ofna- 



" Phil. Trans, vol. v. part ii. p. 71.' 



ture there is any such thing as Avater at all. 

 " What assumes the appearance," say they, 

 " is nothing more than melted ice. Ice is the 

 real element of Nature's making ; and when 

 found in a state of fluidity, it is then in a state 

 of violence. All substances are naturally hard; 

 but some more readily melt with heat than 

 others. It requires a great heat to melt iron; 

 a smaller heat will melt copper; silver, gold, 

 tin, and lead, melt with smaller still ; ice. 

 which is a body like the rest, melts with a 

 very moderate warmth; and quicksilver melts 

 with the smallest warmth of all. Water, there- 

 fore, is but ice kept in continual fusion ; and 

 still returning to its former state, when the 

 heat is taken away." Between these oppo- 

 site opinions, the controversy has been car- 

 ried on with great ardour, and much has been 

 written on both sides ; and yet, when we conn- 

 to examine the debate, it will probably ter- 

 minate in this question, whether cold or heat 

 first began their operations upon water ? This 

 is a fact of very little importance, if known : 

 and, what is more, it is a fact we can never 

 know. 



Indeed, if we examine into the operation? 

 of cold and heat upon water, we shall find 

 that they produce somewhat similar effects. 

 Water dilates in its bulk, by heat, to a very 

 considerable degree ; and, what is more ex- 

 traordinary, it is likewise dilated by cold in 

 the same manner. 



If water be placed over a fire, it grows gra- 

 dually larger in bulk, as it becomes hot, until 

 it begins to boil ; after which no art can either 

 increase its bulk or its heat. By increasing 

 the fire, indeed, it may be more quickly eva- 

 porated away ; but its heat and its bulk still 

 continue the same. By the expanding of this 

 fluid, by heat, philosophers have found a way 

 to determine the warmth or the coldness of 

 other bodies ; for if put into a glass tube, by 

 its swelling and rising, it shows the quantity 

 of heat in the body to which it is applied ; and 

 by its contracting and sinking, it shows the 

 absence of the same. Instead of using water 

 in this instrument, which is called a thermo- 

 meter, they now make use of spirit of wine, 

 which is not apt to freeze, and which is en- 

 dued even with a greater expansion, by heat, 

 than water. The instrument consists of no- 

 thing more than a hollow ball of glass, with a 

 P 



