1838] . WRITINGS OP JOSEPH HENRY. 127 



SECTION V. 



On the Production and Properties of induced Currents of the 

 Third, Fourth, and Fifth order. 



78. The fact of the perfect neutralization of the primary- 

 current by a secondary, in the interposed conductor, led me 

 to conclude that if the latter could be drawn out, or separated 

 from the influence of the former, it would itself be capable 

 of producing a new induced current in a third conductor. 



79. The arrangement exhibited in Fig. 8 furnishes a ready 



Cb 



Fig. 8. — a coil No. 1, h coil No. 2, c coil No. 3, d helix No. 1. 



means of testing this. The primary current, as usual, is 

 passed through coil No. 1, while coil No. 2 is placed over 

 this to receive the induction, with its ends joined to those of 

 coil No. 3. By this disposition the secondary current passes 

 through No. 3; and since this is at a distance, and without 

 the influence of the primary, its separate induction will be 

 rendered manifest by the effects on helix No. 1. When tht 

 handles e, /, are grasped a powerful shock is received, prov- 

 ing 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 suf- 

 ficient intensity to give shocks, could scarcely have been 

 anticipated from our previous knowledge of the subject. 

 The secondar}' current consists as it were of a single wave 



