254" <*" ''*^ ELECTRIC COLUMN. 



and besides it is of no avail, since Mr. Fourcroy himself, 

 and all those who have adopted it, have been obliged to 

 suppose, that this pretended solution bf the water remains 

 dependent on the temperature ; whicli they are obliged to 

 do, otherwise it would be notliing more than my system, 

 with the appearance of refuting it. For, if the enormous 

 quantity o^ water, which sometimes falls in rain from a very 

 limited stratum of air, be not submitted to precipitation by 

 the diminution of heat, it must have been changed into a 

 permanent or aeriformjluid; and in the atmosphere no sen-t 

 h\h\e quantity of vmyjluid of this kind exists, but the atmo- 

 spheric air. Besides, since for this reason it is supposed in 

 that hypothesis, that the evaporated water remains de- 

 pendant on temperaturey very little knowledge in hygrology 

 is required to conclude, that it cannot cease to affect the 

 hygrometer in proportion to its quantity, as is evident from 

 Mr. de Saussure'a experiments and mine. Lastly, with 

 respect to that^t/zd the decomposition of which produces 

 rain, its nature is clearly determined by the following cir- 

 Storms do net cumstance : when we remain in a stratum of air till the end 

 *f tfae"^!**^^"^* ^^ *^^ operations by which a deluge oirain, even with Hght- 

 any chemicaj ning and thunder, has been produced, the residuum, accord- 

 ^*^* ing to all tests, is the same air as before. Such are the 



objections which I have made to Mr. Fourcroy himself, and 

 which he has not answered, or any chemist for him. 

 Deception Art. XIV. These formations and modifications of c/p«rfs', 



from observa- ^j^en viewed onlv over head from the plain, have naturally 



tiOBs on plains, . . , , . ' , , i ,-, • j 



inspired the idea, that by some cause the liberation and 



condensation of evaporated water now and the« take place 

 in a great extent of the upper region of the atmosphere, 

 which water descends and accumulates in the stratum of air 

 where clouds form and produce rain. But this idea pro- 

 ceeds from a want of previous knowledge in hygrology, and 

 of observations on high mountains : for in the first place, 

 whencever, and from whatever cause that quantity of water 

 may be supposed to proceed before any precipitation can 

 take place, even in the first state of vesicular vapour which 

 constitutes clouds, it must be preceded by extreme moisture 

 in the still transparent air, since it is only the excess of that 

 irafer, which is first precipitated in a mist; and when this 



precipitation 



