ELECTRICITY DURING RAIN. 471 



tlie origin of the assumed negative rains, as well as of tbe supposed nega- 

 tive clouds, two errors as yet taught by some authorities. After twenty 

 years of study of electrical meteorology, I believe I have acquired the 

 right to reject many errors, without caring about the names of those by 

 whom those errors were accredited. But, giving a proper interpretation 

 to the facts recorded by diligent and eminent observers, instead of ob- 

 jections to the truth of the i^rinciple I have exposed, we discover in them 

 the proof of what I have said. Many, for instance, upon the authority 

 of Beccaria, afiQrm the production of electricity in pure atmosphere, {del 

 sereno^) and I have demonstrated that this can only take place when, at 

 some distance from the place of observation, rain, hail, or snow is fall- 

 ing. Kow, by a careful perusal of the illustrious electrician's worlds, we 

 see that, instead of a refutation of my principle, there is in them what 

 might entitle him to the right of priority in the discovery. The follow- 

 ing passage from Beccaria's works seems quite clear: '■'■Electricity in pure 

 atmosj)liere is always in excess, and tchenever in serene atmospliere elec- 

 tricity in defect is observed, it has heen carried there by wind from some 

 part of tJie atmosphere^ as distant as it might he, tcherc there are actually 

 clouds, snoic, rain, or hailP It is evident that the diligent observer 

 derives the electricity in such case from a distant region, not serene, 

 and, instead of the influx, believes it to be carried by the wind ; 

 but the fact of electricity becoming negative after the storm had passed 

 the x)lace of observation, and was carried eastward hj a gentle wind, as 

 previously described, would be sufficient to i)reclude the idea of the wind 

 as carrier of negative electricity, even had I not observed, a hundred 

 times, electricity with the most perfect calm. Sui^pressing, therefore, 

 the word cloud in Beccaria's sentence above reproduced, it will remain 

 a fact that negative electricity in serene atmosphere is obtained onlj- 

 when, at a distance from the place of observation, rain, hail, or snow is 

 falling. 



Peltier had observed negative electricity in presence of certain clouds 

 of a dark-bluish color, and thought that their electrical nature might 

 be made known by their color. When clouds at a distance resolve 

 themselves in rain they exactly assume that color described by the French 

 j)hysicist, and the falling rain produces negative electricity. Thus my 

 observations are confirmed, not refuted. 



The existence of clouds loaded with negative electricity pertaining to 

 them has been attributed either to the negative electricity often observed 

 with a fall of rain at the place of observation, or to the same electricity 

 observed in presence of clouds. We have explained how the first is 

 produced; the second is a certain sign of distant rain. On the Vesuvius 

 Observatory clouds often i)ass in such a way as to surround the whole 

 building; yet in many years of continued observations, with fixed and 

 movable conductors, I have never met, under those conditions, with 

 negative electricity. 



