5J30 HISTOUY OF 



CHAP. XXI. 



OF METEORS AND SUCH APPEARANCES AS REaUI.T FROM A 

 ', COMBINATION OF THE ELEMENTS. 



In proportion as the substances of nature are more compound- 

 td and combined, their appearances become more inexplicable 

 And amazing. The properties of water have been very nearly 

 iiscertained. Many of the qualities of air, earth, and fire, 

 have been discovered and estimated ; but when these come 

 to be united by nature, they often produce a result which 

 no artificial combinations can imitate ; and we stand sur- 

 prised, that although we are possessed of all those sub- 

 stances which nature makes use of, she shows herself a much 

 more various operator than the most skilful chemist ever ap- 

 peared to be. Every cloud that moves, and every shower that 

 falls, serves to mortify the philosopiier's pride, and to show him 

 hidden qualities in air and water, that he finds it difficult to ex- 

 plain. Dews, hail, snow, and thunder, are not less difficult for 

 being more conunon. Indeed, when we reflect on the manner 

 in which nature performs any one of these operations, our won- 

 der increases. To see water, which is heavier than air, rising 

 in air, and then falling in a form so very different from that in 

 which it rose ; to see the same fluid at one time descending in 

 the form of hail, at another in that of snow ; to see two clouds, 

 by dashing against each other, producing an electrical fire, which 

 n o watery composition that we know of can eflfect ; these, I say, 

 serve sufficiently to excite our wonder ; and still the more in pro- 

 portion as the objects are ever pressing on our curiosity. Much, 

 however, has been written concerning the manner in which na- 

 ture operates in these productions •, as nothing is so ungrateful 

 to mankind as hopeless ignorance. 



And first, with regard to the manner in which water evapor- 

 ates, and rises to form clouds, much has been advanced, and 

 many theories devised.' All water,' say some, has a quantitj 



• See Note upDii Evaporation, at paf^e 139i 

 J Spectacle de la Nature, vol. ii. 



