- On Hlectro-Dynamic Induction. 227 
coil No. 1, while coil No 2 is placed over this to receive the in- 
duction, with its ends joined to those of coil No.3. By this dis- 
position the secondary current passes through No. 3; and since 
Fig. 8. 
a 
a coil No. 1, 6 coil No. 2, c coil No. 3, d helix No. 1. 
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 the handles a, b are grasped, a powerful 
Shock is received, proving 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 inductions might be 
tained. ‘ 
81. The induction of currents of different orders, of sufficient 
intensity to give shocks, could scarcely have been anticipated 
from our previous knowledge of the subject. The secondary 
current consists, as it were, of a single wave of the natural elec- 
tricity of the wire, disturbed but for an instant by the apansoen 
of the primary ; yet this has the power of inducing another cu 
rent, but little inferior in snare to itself,.and thus elaced 
effects apparently much greater in proportion to the quantity of 
electricity i in motion than the aie current. 
82. Some difference may be conceived to exist in the action 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, aiid the other of a succession of such 
impulses, or a continuous action. It was therefore important to 
investigate the properties of the currents of different orders, 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 current of the 
