to Electricity and Magnetism. 



Fig, 8. 



261 





a coil No. 1, b coil No, 2, c coil No. 3; d helix No. 1. 



the influence of the primary, its separate induction will be 

 rendered manifest by the effects on hehx No. 1. When the 

 handles a, h are grasped a powerful shock is received, pro- 

 ving the induction of a tertiary current. 



80. By a similar but more extended arrangement, as shown 

 in fig. 9, shocks were received from currents of a fourth and 

 fifth order; and with a more powerful primary current, and 

 additional coils, a still greater number of successive induc- 

 tions might be obtained. 



81. The induction of currents of different orders, of suffi- 

 cient intensity to give shocks, could scarcely have been anti- 

 cipated from our previous knowledge of the subject. The se- 

 condary current consists, as it were, of a single wave of the 

 natural electricity of the wire, disturbed but for an instant by 

 the induction of the primary ; yet this has the power of in- 

 ducing another current, but little inferior in energy to itself, 

 and thus produces effects apparently much greater in propor- 

 tion to the quantity of electricity in motion than the primary 

 current. 



82. Some difference may be conceived to exist in the ac- 

 tion of the induced currents, and that from the battery, since 

 they are apparently different in nature; the one consisting, 

 as we may suppose, of a single impulse ; and the other of a 

 succession of such impulses, or a continuous action. It was 

 therefore important to investigate the properties of these cur- 

 rents, and to compare the results with those before obtained. 



83. First, in reference to the intensity, it was found that 

 with the small battery a shock could be given from the cur- 

 rent of the third order to twenty-five persons joining hands ; 

 also shocks perceptible in the arms were obtained from a cur- 

 rent of the fifth order. 



84. The action at a distance was also much greater than 

 could have been anticipated. In one experiment shocks from 

 the tertiary current were distinctly felt through the tongue, 



