414 Prof. Wheatstone on I he Thermo-electric Spark, ^c. 



hitherto discovered is more ancient than the oldest stratified 

 formations known to us ; we cannot even decide the relations in 

 p 'int of age of the most ancient granite to the oldest fossUiferous 

 beds. 



But why, I may ask, should man, to whom the early history of his 

 own species and the rise of nations presents so obscure a problem, 

 feel disappointed if he fail to trace back the animate world to its 

 first origin? Already has the beginning of things receded before 

 our researches to times immeasurably distant. Why then, atter 

 wandering back in imagination through a boundless lapse of years, 

 should we expect to find any resting-place for our thoughts, or 

 hope to assign a limit to the periods of past time throughout which 

 it has pleased an omnipotent and eternal Being to manifest his 

 creative power ? 



But it is not my intention to advert now to these and other 

 points on which I happen to differ from Dr. Buckland. I would 

 rather express the gratification I feel in finding myself in perfect 

 accordance with him on so many subjects. His work is admirably 

 adapted to convey instruction on organic remains, and other de- 

 partments of geology, both to beginners and to those well versed in 

 the science, and is characterized throughout by a truly philosophi- 

 cal spirit, which betrays no desire to adhere tenaciously to dogmas 

 impugned or refuted by the modern progress of science. On the 

 contrary, the author has abandoned several opinions which he him- 

 self had formerly advocated; and although still attached to the 

 theory which teaches the turbulent condition of the planet when the 

 lias and other fossiliferous rocks were formed, and the general in- 

 sufficiency of existing causes to explain the changes which have 

 occurred on the earth, he yet refers in almost all parts of his book 

 to the ordinary operations of nature to explain a variety of phaeno- 

 niena once supposed to be the result of causes different in kind and 

 degree from those now acting. 



I have now, Gentlemen, only to offer you my acknowledgements 

 for the high honour conferred upon me by my election to fill the 

 President's chair for the last two years ; and it is a source of great 

 satisfaction to me to feel assured of the continued prosperity an'd 

 usefulness of the association when 1 resign my trust into the hands 

 of a successor so distinguished for his zeal, talents, and varied ac- 

 quirements as Mr. Whewell. 



LXXVIII. On the Thermo-electric Spark, <^c. Communi- 

 cated by C. Wheatstone, ^5<7., F.R,S., Professor of Experi- 

 mental Philosophy in King^s College, London, 



T^HE following notice of some recent experiments made in 



-■- Italy, on the production of the thermo-electric spark, and 



on the chemical effects of the thermo-electric currents, will, 



no doubt be acceptable to many of your readers. I shall 



