166 MEMOIR OF PELTIER. 



place to a negative descending cuiTent still more powerful. August 6 of this 

 same year, especially, the storm that he was observing presented at least 25 of 

 these inversions. He even ascertained that these sudden inversions did not take 

 place in all their power until the rain precipitated itself from the clouds to fall 

 on the ground ; and, finally, he discovered that all storms were negative, but that 

 the clouds suiTounding them were in general of a contrary electricity, and that 

 this was the reason why the commencement and close of stonns always produce 

 positive signs, while the storm itself gives but negative ones. 



In 1838 Peltier noticed a fact which he afterwards often confirmed, namely : 

 that snow alone never produces electric cun-ents, while on the contrary sleet and 

 hail invariably give them. When they come with snow it is because it is mingled 

 with sleet. Finally, this same year, he called the attention of the Philomathic 

 Society to the fact that the earth and all bodies resting upon it are naturally in a 

 negative state ; but that when in a storm the lower clouds are strongly negative, 

 the eaith and all appurtenant bodies, being beneath them, become positive ; that 

 is, they exist momentarily in a condition opposed to tlwir ordinary state ; and he 

 thinks this change of electric state may be the cause of the general discomfort 

 sufic'red by nervous persons during certain storms. 



We see that Peltier was perfectly prepared by his observations and previous 

 researches for the study of meteorology. He understood electricity thoroughly ; 

 he possessed galvanometers of great sensibility, by the aid of which he could 

 estimate the smallest dA'namic cuixents ; he had invented an electrometer which 

 could measure the smallest static tension ; he had already made both curious and 

 interesting meteorological observations, and he needed but some favorable occa- 

 sion to deliver himself to the study of meteorology with all his characteristic 

 ardor. This occasion the water-spout of Chatenay was not long in furnishing. 



On June 18, 1839, a water-spout laid waste the property of M. Herelle at 

 Chatenay. The insurance c«»mpany refused to pay damages, alleging that water- 

 spouts were not electric phenomena. In order to satisfy himself on this point 

 M. Herelle sought Peltier, whose works had now begun to be known and appre- 

 ciated. Solicited by M. Herelle, Peltier repaired to the spot, and by virtue of 

 his perfect knowledge of electricity soon determined the real character of this 

 phenomenon. He first %\Tote a letter on this subject to the Academy of Science, 

 July 15; later, his ideas becoming still clearer, he presented, October 28, a 

 resume of his researches, and in 1840 published his Treatise on Water-spouts. 



From this moment Peltier found himself engaged for a long time in the study 

 of meteorology ; for, in consequence of his habit of never leaving unexplained 

 a single phenomenon, he felt himself compelled to study the whole science, and 

 with what zeal he did this we shall now see. 



February 3, 1840, Peltier wrote to the academy explaining the fact of the 

 entire destruction of a man by a thunderbolt ; and the same day laid before them 

 a sealed package on the grouping of clouds. May 4, he communicated to this 

 learned body observations of great interest, made by aid of an electric kite, on 

 atmospheric electricity during clear weather. May 25, he made known his 

 researches on the phenomena which take place in the interior of metallic spheres 

 charged with electricity, and deduced from them an explanation of the grouping 

 of clouds. June 1, he complimented the academy by a presentation of his Treatise 

 on Water-spouts ; and, finally, November 30, he presented them with an article 

 in which he demonstrated that the electricity produced by evaporation was only 

 maintained by decrepitation. All these works, however, did not prevent him 

 from continuing his experiments in electricity and his microscopical researches, 

 so that, July 4, he presented to the Philomathic Society the interesting observa- 

 tion of a lucophre produced by efilnx ; and, November IG, made known to the 

 academy his experiments on the origin of the zoosperms of the frog. 



In 1841 Peltier continued to occupy himself with the same ardor on all that 

 concerns meteorology ; he ascertained the resinous tension of the earth, and dis- 



