THE EAIITH. 131 



Stance led Doctor Cheney into a very peculiar tiain of thinking. 

 He suspected that the quantity of water, on the surface of the 

 earth, was daily decreasing. For, says he, some parts of it are 

 continually joined to vegetable, animal, and mineral substances, 

 which no art can again recover. United with these, the water 

 loses its fluidity ; for if, continues he, we separate a few particles 

 of any fluid, and fasten them to a solid body, or keep them asun 

 c(er, they will be fluid no longer. To produce fluidity, a consid- 

 erable number of such particles are required ; but here they are 

 close and destitute of their natural properties. Thus, according 

 to him, the world is growing every day harder and harder, and 

 the earth firmer and firmer ; and there may come a time when 

 every object around us may be stiffened in universal frigidity ! 

 However, we have causes enough of anxiety in this world already, 

 not to '>dd this preposterous concern to the number. 



That air also contributes to divide the parts of water, we can 

 have no manner of doubt ; some have even disputed whether 

 water be not capable of being turned into air. However, though 

 this cannot be allowed, it must be granted, that it may be turn- 

 ed into a substance which greatly resembles air (as we have seen 

 !n the experiment of the seolipile) with aU its properties ; except 

 that, by cold, this new-made air may be condensed again into 

 water. 



But of all the substances which tend to divide the parts of 

 water, fire is the most powerful. Water, when heated into 

 steam, acquires such force, and the parts of it tend to fly oflf 

 from each other with such violence, that no earthly substance 

 we know of is strong eiiough to confine them. A single drop 

 of water, converted into steam, has been found capable of raising 

 a weight of twenty tons ; and would have raised tvventy thou- 

 sand, were the vessel confining it suiBciently strong, and the fire 

 below increased in proportion. 



From this easy yielding of its parts to external pressure, arises 

 the art of determining the specific gravity of bodies by plunging 

 them in water ; with many other useful discoveries in that part 

 of natural philosophy, called hydrostatics. The laws of tins 

 science, which Archimedes began, and Pascal, with some other 

 of the moderns, have much improved, rather belongs to experi- 

 mental than to natural history. Hosvever, I will take leave to 

 mention some of the most striking paradoxes in this branch of 



