Prof. Botto on the Chemical Action ofMagneto^electricity, 441 



if this space is left untouched, and the parts round it be co- 

 vered by lines or etching, the figure will ap{)ear most lumi- 

 nous. 



We would recommend this subject to the notice of the op- 

 tician, as likely to furnish him with a lucrative article of trade. 



AUerly, Nov. 8, 1832. 



LXXIX. Notice on the Chemical Action of the Magneto- 

 electric Currc7its. By Professor Botto, of Turin^. 



\ MONGST the characters which it is important to de- 

 ■^^ terniine with reference to the knowledge of the nature of 

 the magneto-electric currents discovered by Faraday, is that 

 of their chemical action. As decisive of this point, I will state 

 the results I have recently obtained, limiting myself for the 

 present to a mei'e announcement ; since they make part of other 

 results belonging to a series of careful experimental inquiries, 

 intended to clear up certain points of the theory of electro- 

 magnetism, which will be published in due time. 



The apparatus which I used to examine the chemical effi- 

 cacy of the Faradian currents [^Faradiane correnti^ consisted 

 principally of an artificial horse-shoe magnet, and a bar of 

 soft iron surrounded in the middle by a magneto-electric 

 spiral. The extremities of such a bar may, by help of a very 

 simple arrangement, be separated at will from the poles of the 

 magnet, and restored again to their first position with any re- 

 quired degree of rapidity. 



The apparatus is inclosed within a wooden box, and is put 

 into activity by an external handle. The box is surmounted 

 by two i-ods, so connected (moveably) with the internal me- 

 chanism as by means of it to interrupt or re-establish the 

 current, at pleasure, and at the moment most favourable to 

 the production of a spark. When the spark is to be obtained, 

 it is only necessary to connect these rods with the extre- 

 mities of the magneto-electric spiral. When the apparatus 

 is to be adjusted for chemical decomposition, the extremities 

 are to be otherwise arranged, and so that the substance to be 

 decomposed enters into the circuit. 



Water, sulphate of copper, acetate of lead, and other salts 

 in solution were thus submitted to trial. At first, minute 

 quantities of the substances were acted upon, because of the 

 feeble power of the apparatus (the magnet scarcely lifting six 

 pounds, Piedmontese), and the presumed relative tenuity of 

 the current : but 1 was not long in ascertaining that such was 



• Communicated by the Author. 



Third Seiies. Vol. I. No. 6. Dec. 1832. y L 



