•HYGROLOGY; AND ITS CONNECTION WITH METEOROLOGY. 291 



sions are but inductive reasonings, according* to the known 

 facts, which therefore are liable to be subverted by the facts 

 being multiplied, whatever be the issue, no humiliation ought 

 to be experienced, as the parties will moult no feather. 

 I have the honour to be. 

 Dear Sir, 

 Your most faithful Servant, 



GEORGE PEARSON. 



IX. 



On Hygrologij, Uygrometry, and their Connexions ivith the 

 Phenomena observed in the Atmosphere. By J. A. De Luc, 

 Esq. F. R. S. 



To W. Nicholson, Esq. 

 SIR, 



IN the third part of rny paper on the electric coliunn, pub- Atmospheric 

 ' ^ ' "^ phenomena im- 



lished m your Number 124, for December, 1810, where portant to the 

 I have considered that instrument as an aerial electroscope, I knowledge of 

 1 I I . /- , . .1 1 7-1 ^"'^ nature of 



nave shown the importance of studying all the atmospheric phe- water ; 



nomena, before a final decision could be obtained of the ques- 

 tion agitated for some time, on the nature of water; whether 

 it is a compound or a simple substance ; a question which em- 

 braces the whole theory of chemistry. Especially I hope to 

 have made it evident in that paper, that, since atmospheric phe- 

 nomena are to be considered in the solution of the above ques- 

 tion, we ought to study particularly all those of the electric and partlcu- 

 fluid in the atmosphere ; to which we might be led by the |;'J^[,'|'°^7t^°"" 

 phenomena of the aerial electroscope, provided we did not con - electricity, 

 nect them with arbitrary hypotheses, nor forget to t^ike into 

 consideration the nature of the electric fluid, which, from the 

 great phenomena of lightning and thunder, has evidently a 

 'great share in meteorological appearances. My papers. Sir, 



* Experientls ordo primo lumen accendit, deinde per lumen iter de- 

 monstrat, incipiendo ab experientia ordinata et digesta, atque ex ea 

 ediicendo axinmata, atque ex axiomatibus constitutis rursus nova experi. 

 menta.— Nov. Organum F, Baconis. 



U2 in 



