Additional Notes. 449- 



Kiel, succeeded In charging electrical batteries o^ 140 feet 

 square, by a single contact with the pile of Volta, and 

 proved that this pile is a true exxitatory apparatus of electri- 

 city. They melted, by the electricity of this apparatus, a 

 large portion of iron wire, and even wire of platina. The 

 communication of Dr. Van Marum on tliis subject, to 

 Sig. VoLTA (see Annates de Ciiimie^ torn. 40), is highly 

 interesting. He charged both single jars and large batteries 

 by means of tlie pile, and always found that tiiey were charged 

 to the same degree of intensity with that w^hich the pile it- 

 self indicated to the Electrometer. He found, also, that the 

 shocks given by the battery, when charged from powerful 

 electrical machines, were not perceptibly different from those 

 given by batteries charged from the pile. He found, further, 

 that piles which consist of the same number of plates, but 

 of different diameters, gave equal intensities and equal shocks; 

 but that those made of larger plates are considerably more 

 powerful in fusing metals. 



Dr. Bostock's Theoiy of Galvanism. 



John Bostock, M. D. of Great-Britain, has offered the 

 following Galvanic theory: — ^He thinks that the phenomena 

 of the pile of Volta may all be easily explained by admit- 

 ting the truth of the following postulates. 



1. That the electric fluid is always generated or liberated 

 when a metal, or any oxydable substance, is united to oxygen. 



2. That the electric fluid has a strong attraction for hydro- 

 s'"' 



3. That when the electric fluid, in passing along a chaim 



of conductors, leaves an oxydable substance to be conveyed 

 through water, it unites itself to hydrogen, from which it is 

 again disengaged, when it returns to the oxydable conductor. 



'The Jirst of these propositions Dr. Bostock considers as 

 almost proved by the experiments of Fabroni, Davy, 

 and WoLLASTON. The second and third, have not beeii di- 

 rectly established by experiment, but arc viewed by Dr. Bo- 

 stock as highly probable. 



Dr. Bostock accounts for the operations carried on at 

 the end of the wire, in the interrupted circuit, as discovered 

 by Nicholson, in the following manner. 



As the current of the electric fluid appears to pass from 

 the zinc, or plus end of the apparatus, to the silver end, it 



3M 



