352 Experiments and Remarks on Galvanism, 



the lime would, no doubt, become much more sensible if the 

 ammoniacal gas were received in a strong solution of the 

 muriat of lime. 



If the ammonia produces a precipitate with salts having a 

 base of alumine, it is because this earth has less solubility 

 than lime, even when it is combined with the portion of the 

 acid which it retains while it is precipitated. 

 [To be continued.] 



XLIII. Experiments and Remarks on Galvanism, A Letter 

 from a Correspondent to the Editor, 



JLJlAVING read with much pleasure, in your very valu- 

 able monthly publication, the several opinions and experi- 

 ments respecting the influence excited in the pile of Volta, 

 I take the liberty of submitting to you some observations on 

 the same subject. 



It has been said by some very ingenious experimentalists 

 that the oxydation of one side of the plates, or the difference 

 of oxydation in the two metals, or between one metal and 

 different fluids, is the cause of the production of the galvanic 

 influence. I find that the acids increase the power of my 

 pile, and I also find, when the papers or cards are moistened 

 with the pure alkalies, and particularly with a solution of pure 

 ammonia, that the effect is much greater than by any other 

 substance. This fact is, I believe, sufficient to prove that the 

 oxydation of the metals is not the cause of the phaenomenon. 



It is very convenient to use the alkalies in this manner, a3 

 it does not require so much trouble to clean the metals, or 

 to keep the pile in order. 



I took ten saucers, and placed in each a plate of silver and 

 a plate of zinc ; I connected these metals in the several saucers 

 together, by means of slips of tin-foil, and completed the cir- 

 cuit by means of wires in water. I first filled these saucers 

 with salt and water, and found that the wires in the water 

 produced a trifling effect : some few air-bubbles escaped, 

 which proved that the influence was excited, I then re- 

 moved 



