122 EULOGY ON ALEXANDER VOLTA. 



aclniitted the itieiitity of ligbtning and electricity, so conclusively proved 

 by the experiment of Franklin and of Marly-la- Ville ; but the small 

 number of sparks proceeding from the rod, and their minuteness, created 

 doubts as to the possibility of exhausting the immense amount of ful- 

 minating matter with which a storm-cloud must be charged. The 

 frightful experiments made by Romas de Nerac did not overcome their 

 opi)osit!on, because this experimentalist used a kite with a metallic 

 cord, which rose several hundred feet, to draw down the thunder from 

 the very regions of the clouds. Soon, however, the deplorable death ot 

 Kichman, August G, 1753, occasioned by a simple discharge from an 

 ordinary insulated lightning-rod which this distinguished i^hysicist liad 

 placed on his house in Saint Petersburg, threw new light upon the sub- 

 ject. The learned saw in this tragic death an explanation of the passage 

 in which Pliny, the naturalist, relates that TuUus Ilostilius was struck 

 by lightning for not having been sufficiently careful in the performance 

 of certain ceremonies by means of which Numa, his predecessor, forced 

 the lightning to descend from the skies. On the other side, and this 

 was of more importance, physicists, without prejudice, found in this 

 same event a fact which had before been wanting, namely, that under 

 certain circumstances a metallic rod, slightly elevated, draws down from a 

 storm-cloud not only inappreciable sparks, but genuine torrents of 

 electricity. Accordingly, from this time discussions relating to the 

 efficacy of lightning-rods are without interest, not even excepting the 

 animated debate as to whether lightning-rods should terminate in a 

 point or ball, which for some time divided the English scientists. iSTo one 

 is ignorant now that George III was the promoter of this i)olemic — that 

 he was in favor of rods terminating in balls, because Franklin, then his 

 successful antagonist in political questions of vast importance, required 

 they should terminate in points ; but this discussion, taking all things 

 into consideration, belongs rather, though a matter of much moment, to 

 the history of the American Revolution than to that of science. 



The results of the experiment of Marly were scarcely known, when 

 Lemonnier, of this academy, placed in his garden at Saint-Germain-en- 

 Lage a long vertical metallic rod,' insulated by some newly invented 

 precautions, and from this time clusters of electrical sparks (July and 

 September, 1752) were produced, not only when the thunder rumbled, not 

 only when the sky was overcast with threatening clouds, but even when 

 it was perfectly' serene. A beautiful discovery was thus the result of 

 apparently the most insigniticant niodiflcation of Dalibard's original 

 apparatus. 



Lemonnier discovered without much difficulty that this serene-day 

 lightning, whose existence he had just revealed, was subject every 

 twenty-four hours to regular variations of intensity. Beccaria de- 

 lineated the laws of this diurnal periodicity by means of excellent ob- 

 servations. He, moreover, established the important fact that at all 

 seasons, at all heights, whatever the direction of the wind, the electricity 

 of a serene sky is invariably positive. 



