THE EARTH 71 



ter that mix with its earth ; and, deprived of this fluid, it becomes n 

 mass of shapeless dust and ashes. 



From hence we see, as was above hinted, that this most fluid body, 

 when mixed with others, gives them consistence and form. Water, 

 by being mixed with earth and ashes, and formed into a vessel, when 

 baked before tli3 fire, becomes a coppel, remarkable for this, that i* 

 will bear the utmost force of the hottest furnace that art can contrive. 

 So the Chinese earth, of which porcelain is made, is nothing more 

 than an artificial composition of earth and water, united by heat ; and 

 which a greater degree of heat could easily separate. Thus we see 

 a body, extremely fluid of itself, in some measure assuming a new na- 

 ture, by being united with others : we see a body, whose fluid and 

 dissolving qualities are so obvious, giving consistence and hardness 

 to all the substances of the earth. 



From considerations of this kind, Thales, and many of the ancient 

 philosophers, held that all things were made of water. In order to 

 confirm this opinion, Helmont made an experiment, by divesting a 

 quantity of earth of all its oils and salts, and then putting this earth, 

 so. prepared, into an earthen pot, which nothing but rain-water could 

 enter, and planting a willow therein ; this vegetable, so planted, grew 

 up to a considerable height and bulk, merely from the accidental as- 

 persion of rain-water ; while the earth, in which it was planted, re- 

 ceived no sensible diminution. From this experiment, he concluded, 

 that water was the only nourishment of the vegetable tribe ; and that 

 vegetables, being the nourishment of animals, all organized substances^ 

 therefore, owed their support and being only to water. But this has 

 been said by Woodward to be all a mistake : for he shows, that water 

 being impregnated with earthy particles, is only the conveyer of such 

 substances into the pores of vegetables, rather than an increaser 

 of them, by its own bulk : he shows that water is ever found to afford 

 much less nourishment, in proportion as it is purified by distillation. 

 A plant in distilled water, will not grow so fast as in water not dis- 

 tilled : and if the same be distilled three or four times over, the plant 

 will scarce grow at all, or receive any nourishment from it. So that 

 water, as such, does not seem the proper nourishment of vegetables, 

 but only the vehicle thereof, which contains the nutritious particles, 

 and carries them through all parts of the plant. Water, in its pure 

 state, may suffice to extend or swell the parts of a plant, but affords 

 vegetable matter in a moderate proportion. 



However this be, it is agreed on all sides, that water, such as we 

 find it, is far from being a pure simple substance. The most genuine 

 we know is mixed with exhalations and dissolutions of various kinds ; 

 and no expedient that has been hitherto discovered, is capable of pu- 

 rifying it entirely. If we filter and distil it a thousand times, accord- 

 ing to Boerhaave, it will still depose a sediment : and by repeating 

 the process we may evaporate it entirely away, but can never totally 

 remove its impurities. Some, however, assert, that water, properly 

 distilled, will have no sediment ;* and that the little white speck 

 which is found at the bottom of the still, is a substance mat entt'is 



* Hill's History of Fossils. 



