92 HISTORY OF GALVANISM. 



deoxidated, and the action of the pile ceases. We 

 are nq,t informed whether, in this case, any visible 

 change is produced on the surface of the metals, or 

 whether all access of moisture was very scrupu- 

 lously prevented in the instrument upon which 

 these experiments were made.* 



Hachette The account of De Luc's pile had been published 

 sormes's f r some time, when a claim of priority of inven- 

 plle * tion was made by Hachette, in favour of himself 

 and Desormes, stating that they had formed a dry 

 pile so long back as the year 1803. It is difficult 

 to decide upon the merit of such claims ; but as a 

 general principle it is always proper, in these 

 cases, to adhere to the date of publication, unless 

 they can be substantiated by written documents of 

 unexceptionable authority. In the present instance, 

 however, it would appear, that the original pile, as 

 formed by Hachette and Desormes, is by no means 

 entitled to the appellation of dry, and indeed does 

 not appear to be analogous to De Luc's instrument, 

 for it is described as having been constructed with 

 paste or size between the plates ; and we are ex- 

 pressly told that, in proportion as the moisture 

 was evaporated, the action of the apparatus was 

 diminished.! 



children's While Sir H. Davy and De Luc were thus en- 

 larging our knowledge of the powers of galvanism 

 as a chemical agent, and of the means by which 



* Journ. of Science and the Arts, ii. 161. 

 f Ann. de Chim. et Phys. ii. 76 ; see also Biot in Ann. de 

 Chim. xlvii. 15. 



