Intelligence and Miscellaneous Articles. 219 



form of the stereoscope had ever made its appearance. I now, how- 

 ever, take the very earliest opportunity of making the acknowledge- 

 ment, and hope you will be able to give it a place in your forth- 

 coming Number. 



I am. Gentlemen, 



Respectfully, 

 Edinburgh, Feb. 10, 1857- James Elliot, 



ON INDUCTION. BY A. MASSON. 

 The object of these experiments is to establish the truth of the 

 following facts, upon which the whole theory of induction reposes : — 



1. All electrical currents, whatever be their tension, produce the 

 same phccnomena of induction. 



2. The induced currents of different orders are composed of two 

 systems of currents equal in quantity, but possessing different inten- 

 sities. (To assimilate voltaic currents to the discharges of Ley den bat- 

 teries, the two secondary currents produced by the rujitureand esta- 

 blishment of the primary current, must be taken.) 



3. The currents which have the highest tension are direct for the 

 secondary current, and inverse for the currents of other orders. 



4. The physiological and magnetic effects of the currents, as well 

 as the elevation of temperature, are produced by instantaneous 

 actions, which only depend on the quantity of electricity and the 

 tension of the current, and by no means on the duration of its 

 action. The quantity of chemical action, the total heat evolved in 

 a circuit, and the deviation of a galvanometer, are independent of 

 the tension and time, and remain always proportionable to the total 

 quantity of electricity set in motion. 



Voltaic induction. — The secondary current of Ruhmkorff's appa- 

 ratus decomposes water abundantly by the employment of poles 

 composed of very fine platinum wires placed in tubes of glass, to one 

 extremity of which they are soldered ; these wires dip into the 

 fluid 1 or 2 millims., and the gases disengaged at each pole form a 

 very pure detonating mixture. 



The galvanometer remains stationary, or undergoes oscillations 

 due to the double current ; by producing a spark in the induced 

 circuit, one of the currents is nearly destroyed ; the decomposition 

 of acidulated water becomes polar, and the deviation of the galvano- 

 meter is certain ; like the voltameter, it indicates a direct induced 

 current. 



A tertiary current gives a detonating mixture ; it has no action 

 on the galvanometer. I have not been able to procure an apparatus 

 capable of producing a spark for the tertiary voltaic current. I hope 

 soon to be able to operate upon the currents of different voltaic 

 orders, as upon the secondary current. 



Induction by the discharge of batteries. — I charge a condenser by 

 the Ruhmkorif s apparatus, employing the precautions indicated in 

 my Eludes de Photorm'lrie electriqxie ; I then obtain a primary 

 current formed of successive discharges sufficiently close together 

 to give the effects an apparent continuity. The circuits disposed 

 Q2 



