Eloge of' Alexander Volta. 5 



nomena, such, for example, as inflammable earth and burning 

 fountains, were owing to a similar cause ; but Volta knew well 

 how far nature sports with our weak conceptions, to give way to 

 mere analogies on slight grounds. He visited the celebrated dis- 

 tricts of Pietra Mala and Velleja ; he carefully weighed all that 

 he read in books of travels relating to analogous places, and at 

 last established, on the most satisfactory evidence, in opposition 

 to the ordinary opinion, that these phenomena do not depend on 

 the presence of petroleum, naphtha, or bitumen; but that a dis- 

 engagement of inflammable gas is the only cause. I am of opi- 

 nion, however, that we may be permitted to doubt, whether Vol- 

 ta has proved so satisfactorily that this gas originates, in all cases, 

 in a maceration of animal and vegetable substances. 



Our illustrious associate possessed, in a high degree, two qua- 

 lities which are rarely found united, a creative genius, and the 

 power of assiduous application. He never abandoned a subject 

 without having regarded it in all its aspects, and having de. 

 scribed, or at least indicated, the vanous instruments which sci- 

 ence, industry, or mere curiosity, might derive from it. Thus 

 some experiments regarding the inflammability of the air in 

 marshes, gave rise first to the electrical gun and pistol, of which 

 it would be superfluous to speak, since they have passed from 

 philosophers into the hands of mountebanks, and form the daily 

 amazement of the crowds in our public places ; secondly, the 

 perpetual lamp of oxygen gas, so general in Germany, and 

 which, by a most ingenious application of the electrophorus, 

 kindles of its own accord when wanted ; and finally, the Eudio- 

 meter, a valuable means of analysis which chemists apply to so 

 many useful purposes. 



The discovery of the composition of atmospheric air has given 

 rise, in our time, to this important question in natural philoso- 

 phy ; — whether the proportion in which the two principal con- 

 stituent principles of air are united, varies with the succession of 

 ages, the position of places, and with the change of seasons ? 



When we reflect that men, quadrupeds, and birds, continually 

 consume, in the act of respiration, one of these principles only, 

 viz. the oxygen gas ; that this same gas is the indispensable ali- 

 ment of combustion in our domestic fires, in workhouses, and fur- 

 naces ; that not a candle nor a lamp can be lighted, nor a fire of 



