Miscellanies. 197 



the series of sparks produce a continued sensation of light. By 

 means of this apparatus, sparks may be obtained as strong as with 

 an electrical machine. — Rev. Encyc. Sept. 1832. 



2. On the chemical action of magneto-electric currents ; by G. D. 

 Botto, Professor of Natural Philosophy in the University of Turin 

 Among the qualities of the magneto-electric currents discovered by 

 Faraday, which it is important to ascertain, is that of their chemical 

 action. The results which I have recently obtained appear to be 

 decisive, but 1 shall, at present, confine myself to a simple announce- 

 ment of them, as they constitute a part of other labors relative to a 

 series of experimental researches, which I intend hereafter to pub- 

 lish, the object of which is to clear up some points of the doctrine 

 of electro-magnetism* 



The apparatus which 1 employed in studying the chemical effica- 

 cy of the currents of Faraday, is composed essentially of an artificial 

 horse shoe magnet, and a bar of soft iron, surrounded, in the middle, 

 with an electro-magnetic spiral. The extremities of this bar, by 

 means of a simple contrivance, may be detached from the poles of 

 the magnet, and reunited with them, as rapidly as may be desired. 



The apparatus is enclosed in a wooden box, and moved by a 

 handle without. The box is also surmounted by two rods, connect- 

 ed, at pleasure, with the interior mechanism, so as to establish or in- 

 terrupt the circuit at the moments favorable to the production of the 

 spark. Hence, when the spark is to be produced, the extremities of 

 the spiral are suitably connected with the rods ; but when the instru- 

 ment is to be used for decompositions, those extremities are so dis- 

 posed that the substance to be decomposed may be introduced into 

 the circuit. 



I have experimented in this manner upon water, acetate of lead, 

 and other saline solutions, using at first very small doses, on account 

 of the feebleness of the instrument, (the magnet sustained scarcely 

 six pounds or 2966 grammes,) but I soon discovered that the energy 

 of the current was sufficient to act successfully upon larger quantities. 

 I attached to a small bell glass two platina wires, to serve as con- 

 ductors. They were fastened, by lac wax, into two holes perforated 

 in the sides. The glass was filled with water, rendered more con- 

 ductible by a few drops of a solution of soda, and inverted in a dish 

 filled with the same fluid. Having connected the platina wires with 

 the electro-magnetic spiral, I put the apparatus in motion. Scarcely 



