EULOGY ON ALEXANDER VOLTA. 127 



and i)roviDg it to be the basis of a very curious branch of meteorology. 

 A few words wdl suffice for this. 



When the insulated metallic vessel in which the water evaporates* 

 becomes electric, this water derives, from the bodies it touches, not 

 only heat but also electricity, in order, Yolta says, to pass from a liquid 

 to an aeriform state. The electric fluid is, then, an integral part of the 

 large masses of vapors which are daily forming at the expense of the 

 seas, lakes, and rivers. These vapors, as they rise, find in the high 

 regions of the atmosphere a degree of cold which condenses them. The 

 constituent electric fluid is then liberated and accumulated, and the 

 feeble couductibility of the air prevents its returning to the earth, whence 

 it came, except in the form of rain, snow, hail, or some violent discharge. 



Thus, on a stormy day, according to this theory, the electricity whose 

 dazzling effulgence darts from east to west, from north to south, whose 

 deep thunderings echo far and near, and which, hurled to the earth, 

 leaves in its course destruction and death, is but the result of the daily 

 evaporation of water, the inevitable consequence of a phenomenon de- 

 veloped by shades so insensible as to be imperceptible to our senses. 

 "When effects are compared to causes, nature, we must acknowledge, 

 presents most wonderful contrasts, 



THE VOLTAIC TILE. 



I have now reached one of those rare epochs in which an important 

 and unexpected fact, so often the result of some auspicious accident, 

 in the hands of genius becomes the source of a scientific revolution. 



A detailed description of the wonderful effects produced by insig- 

 nificant causes, would, perhaps, be as interesting in the history of the 

 sciences as in that of nations. If some savant should ever undertake to 

 sketch it, that branch of physics properly called galvanism would 

 occupy one of the first places in it. In fact, it can be proved that the 

 immortal discovery of the pile, springs, in a very direct manner, from 

 a slight cold with which a lady of Bologna was attacked in 1790, who 

 was ordered by her physician a dish of frog-soup. 



Several of these animals, prepared for the purpose by Madame Gal- 

 vaui's cook, were lying on a table at the time of an accidental discharge 

 of an electrical machine at some distance. The muscles, although not 

 tou(;hed by the sparks, evinced, at the moment of the discharge, the 

 most decided contractions. The experiment, repeated with all kinds of 

 animals, succeeded equally well, whether the electricity were artificial 

 or natural, positive or negative. 



This i)heuomenon was very easily explained on the well-known prin- 

 cii)lc of induction, the electricity of the discharge disturbing by repul- 

 sion at a distance the natural electricity of the frog. Uad it happened 

 to some experienced physicist, familiar with the properties of electricity, 



• It is now known that this experiment does not succeed when distilled water is used. 



