118 EULOGY ON ALEXANDER VOLT A. 



he" hastened to visit the celebrated marshes of Fietra Mala and Velleja. 

 He thoroughly examined all he could find in difterent travels in similar 

 localities, and then succeeded in establishing, with comi)lete proof, and 

 contrary to received opinion, the fact that these phenomena did not 

 depend upon the presence of petroleum, naphtha, or bitumen ; he dem- 

 onstrated, moreover, that it was caused alone by the disengagement 

 of inflammable gas. But has Volta proved, with the same accuracy, 

 that this gas has, in all places, its origin in the maceration of animal 

 or vegetable matter? I think we may be allowed to question this. 

 The electric spark had been, at an early date, used to inflame certain 

 liquids^ certain vapors, and different gases, such as alcohol, the smoke 

 of a candle just extinguished, and hydrogen gas; but all these experi- 

 ments were made in the open air. Yolta was the lirst to make them in 

 closed vessels, (1777.) He is therefore the originator of the apparatus 

 used by Cavendish in 1781 for combining the separated elements of 

 water by synthesis, so as to form anew the decomposed body from its 

 two constituent gaseous elements. 



Our distinguished associate possessed in the highest degree two 

 qualities rarely found united, a creative genius and great iiowers of 

 application. He never abandoned a subject without examining it in all 

 its phases, without describing, or at least pointing out, the various 

 aids which science, ingenuity, and even mere curiosity might bring to 

 bear upon it. Thus several experiments on the inflammable nature of 

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

 it would be superfluous to dwell here, as they have passed from the 

 hands of jihysicists into those of the showman, and, in public places, 

 are daily exhibited to the admiring gaze of gaping idlers. Then the 

 'perpetual hydrogen-gas lamp, so generally known in Germany, which, 

 by the most ingenious application of the electrophorus, lights itself when 

 needed, and, finally, the eudiometer, the valuable instrument of analysis, 

 which has been so useful to chemists. 



The discovery of the composition of atmospheric air has given rise to 

 this momentous question in natural philosophy: Does the proportion, 

 in which the two component parts of air are found united, vary with the 

 successive revolutions of ages, and according to locality and the changes 

 of seasons "? 



When one reflects that all numkind, all the beasts of the earth and 

 fowls of the air are constantly consuming, in the act of breathing, one 

 of these two components, oxygen gas ; that this same gas is the indis- 

 pensable food of combustion in our homes, in workshops and vast fac- 

 tories; that a candle or lamp is not lighted without absorbing it; that, 

 finally oxygen plays the chief part in the phenomena of vegetation, it 

 may readily be imagined that in the long run the atmosphere varies 

 sensibly in its composition ; that at some future time it will become unfit 

 for respiration; that then all the animal creation will be extinguished, not 

 in consequence of one of those physical revolutions of which geologists 



