252 HYGROLOGY, AND ITS CONNECTION WITH METEOROLOGY. 



in the last numbers of your Journal, were destined to show, 

 from our own experiments and atmospherical observations, what 

 are the nature of the electric fluid, and its interference in me- 

 teorological phenomena ; and I now come again to the same 

 subject, under another point of view. 

 Rain not from I. My observations of the aerial electroscope, published in 

 moisture in the y^^^^ jyj^ 5^4, show, that the changes in the phenomena exhi- 

 bite J by this instrument have no connexion with the state of 

 moisture in the ambient air. I proved also, in the same paper, 

 this important point in meteorology, that rain does not proceed 

 from a moisture actually existing in the atmosphere. This, if 

 it be certsin, overturns the new theory of chemistry ; for thus 

 butthepon- Tain cannot proceed from any other cause than that of a decom- 



derabie partof poA'z/ion of the atmospheric air itself, a fluid sui fj-eneris, the 

 the air itself. , , , ^ , . , , i^ > 



ponderable part or which must be water. 



Grounds of the 2. But this conclusion rested on the indications of the hygro- 



eonc usion. 'meter, Mr. De Saussure's observations, and my own, on high 



mountains 3 in the very region of the atmosphere we saw the 



clouds forming around us, and pouring rain, while an instant 



before our hygrometers testified, that there was very little 



Canthehygro- moisture in the air. But here a question arises : is the hysro- 

 meter be de- . , , , , - , ,- 



pendedon? Tweifer an mstrument to be depended upon, lor the purpose 01 



indicating the real quantity of moisture, or evaporated water, 



mixed with the air, in the place where it is observed ? 



Thisanirnpor- 3^ This, Sir, is a very important question, as well in natural, 

 tant question, . . , , ., , ,r • . , 



as m experimental philosophy ; and I wish, through your valua- 



able Journal, to attract the attention of your readers to this 

 instrument, I had very little hope of success on this point, 

 when I wrote my preceding papers in your Journal ; because, 

 from a circumstance which I sliall explain hereafter, none of 

 my hygrometcis could be found ; but it is not the case now. 

 Progress made 4. I had already made some progress in the correspondent 

 m the inquiry, j-esearches of the indications of the hygrometer, and the phe- 

 nomena of rajrt and_/aif zi't-a^Aer, when, in 1/86, I published 

 in Loudon my work. Ideas sur la Meteorologie'*' ; but I had 

 carried them much farther, when I delivered to the Royal 

 Society my papers on hygrology and hygrometry, published 



* T]?is work may be had of Messrs. Dulau aud Co, booksellers ia 

 Soho Square. 



