THE EARTH. 



49 



fire, becomes a coppel, remarkable for this, 

 that it will bear the utmost force of the hot- 

 test 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. 

 Tli us we see a body, extremely fluid of it- 

 self, in some measure assuming a new nature, 

 l>y being united with others : we see a body, 

 whose fluid and dissolving qualities are so ob- 

 * ious, giving consistence and hardness to all 

 ihe 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 ex- 

 periment, 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 plant- 

 ing a willow therein ; this vegetable, so plant- 

 ed, grew up to a considerable height and 

 bulk, merely from the accidental aspersion 

 of rain-water; while the earth, in which it 

 v/as planted, received no sensible diminution. 

 From this experiment, he concluded, that 

 water was the only nourishment of the vege- 

 table tribe; and that vegetables, being the 

 nourishment of animals, all organized sub- 

 stances, therefore, owed their support and 

 being only to water. But this has been said 

 by Woodward to be a mistake: for he shows, 

 that water being impregnated with earthy 

 particles, is only the conveyer of such substan- 

 ces into the pores of vegetables, rather than 

 an increaser of them by its own bulk : and 

 likewise, that water is ever found to afford 

 so much less nourishment, in proportion as it 

 is purified by distillation. A plant in distil- 

 led water will not grow so fast as in water not 

 dis'.illed: and if the same be distilled three 

 or four times over, the plant will scarcely grow 

 ut all, or receive any nourishment 1'rom it. So 

 that water, as such, does not seem the proper 

 nourishment of vegetables, but only the vehi- 

 cle thereof, which contains the nutritious par- 

 ticles, and carries them through all parts of 



Hill's History of Fossils. 



'' Hermetically sealing a glass vessel, means no more 

 tlian beating the mouth of the phial red hot ; and thus, 



the plant. Water, in its pure state, may suf- 

 fice 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 disso- 

 lutions of various kinds ; and no expedient 

 that has been hitherto discovered, is capable 

 of purifying it entirely. If we filter and distil 

 it a thousand times, according to Boerhaave, 

 it will still depose a sediment : and by repeat- 

 ing the process we may evaporate it entirely 

 away, but can never totally remove its impu- 

 rities. Some, however, assert, that water, 

 properly distilled, will have no sediment ; a and 

 that the little white speck which is found at 

 the bottom of the still, is a substance that en- 

 ters from without. Kircher used to show in 

 his Museum, a phiai of water, that had been 

 kept for fifty years, hermetically sealed ; b du- 

 ring which it had deposed no sediment, but 

 continued as transparent as when first it was 

 put in. How far, therefore, it may be brought 

 to a state of purity by distillation, is unknown; 

 but we very well know, that all such water 

 as we every where see, is a bed in which 

 plants, minerals, and animals, are all found 

 confusedly floating together. 



Rain-water, which is a fluid of Nature's own 

 distilling, and which has been raised so high 

 by evaporation, is nevertheless a very mixed 

 and impure substance. Exhalations of all 

 kinds, whether salts, sulphurs, or metals, make 

 a part of its substance, and tend to increase 

 its weight. If we gather the water that falls, 

 after a thunder-clap, in a sultry summers day, 

 and let it settle, we shall find a real salt stick- 

 ing at the bottom. In winter, however, its 

 impure mixtures are fewer, but still may be 

 separated by distillation. But as to that which 

 is generally caught pouring from the tops of 

 houses, it is particularly foul, being impreg- 

 nated with the smoke ol the chimneys, the va- 

 pour of the slates or tiles, and with other im- 

 purities that birds and animals may have de- 

 posited there. Besides, though it should be 



when the glass is become pliant, squeezing the mouth to- 

 gether with a pair of pincers, and then twisting it six or 

 seven times round, 'vhich effectually closes it up. 



