of Electro-magnetic Experiments. i55 



produced by the action of an excited helix. The action ofan 

 excited body is the production of an opposite excitement on 

 any body in its proximity, which induction increases its own 

 capacity for electricity. Supposing magnetized substances to 

 be merely modified instances of this seemingly universal law, 

 all their properties may easily be explained. 



4th. The power of the battery is not increased, but dimi- 

 nished, by the helix; for, after passing through one helix, its 

 power of exciting another is lessened, nor will it affect a gal- 

 vanometer so much. If it were increased, judging by the spark 

 and shock, and supposing these to arise from such increase, it 

 ought to have acquired an intensity which would easily carry 

 it through any length of wire. 



When 400 drachms of water and 12 of muriatic acid were 

 used, the effect was transitory ; but the spark was very brilliant 

 with the helix alone, less brilliant with a magnet having 12 feet 

 more wire than the helix, less still with a smaller magnet. 

 The shock with the helix was stronger than with the larger 

 magnet ; but when 400 drachms of water, 8 of sulphuric acid, 

 and h of nitric acid were used, the spark from the helix re- 

 mained the most brilliant, but the shock from the magnet be- 

 came stronger than from the helix. To get a shock at a maxi- 

 mum from the helix, contact must be rapidly broken; from 

 the magnet, slowly. The magnet had 600 feet of w ire coiled 

 in three helices ; the helix 588 feet in seven coils. The shock 

 was considerably increased when two persons dipped their 

 hands into the vessels containing the solution of salt; at the 

 same time each received a greater shock than when only one 

 person formed the communication. 



If the mercuiy be not clean, or if some of the battery charge 

 be found upon its surface, neither shock nor spark will be ob- 

 tained, because as soon as the wire leaves the mercury, con- 

 tact for the battery, as its electricity is of very low tension, 

 ceases; but the other fluid will conduct away the electricity, 

 from whence arise the shock and spark. If one extremity of 

 the helix, or one wire of the battery, be lifted out of the mer- 

 cury in contact with the wire leading from the same cup to the 

 solution of salt, no shock will be felt. 



A very cheap, permanent, and convenient apparatus, on the 

 same principle i.s that submitted to the Society, may be con- 

 structed ; one which woidd bear to the galvanic battery of a 

 single circle the same relation as the Leyden jar to the elec- 

 trical machine. Like the Leyden jar, it may be made a ma- 

 gazine of power, ready to be exerted on any object the expe- 

 rimenter niay desire; but it is not frail and perishable, does 

 not demand much care nor attention, does not depend on the 



