228 Contributions to Electricity and Magnetism. 
third order to twenty-five persons, joining hands ; also shocks per- 
ceptible in the arms were obtained from a current 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 ter- 
tiary current were distinctly felt through the tongue, when helix 
No. 1, Fig. 8, was at the distance of eighteen inches above the 
coil transmitting the secondary current. 
5. The same screening effects were pro- - Fig. 9. 
duced by the interposition of plates of metal %, 
between the conductors of the different or- 
ders, as those which have been described in 
reference to the primary and secondary cur- 
rents. 
86. Also when the long helix is placed 
over a secondary current generated in a short 
coil, and which is therefore, as we have be- 
fore shown, one of quantity, a tertiary cur- 
rent of intensity is produced. 
gain, when the intensity current of 
the last experiment is passed through a sec- 
ond helix, and another coil is placed over 
this, a quantity current is again produced. 
Therefore, in the case of these currents, as 
in that of the primary, a quantity current can 
be induced from one of intensity, and the con- 
verse. By the arrangement of the apparatus 
as shown in Fig. 9, these different results 
are exhibited at once. The induction from 
coil No. 3 to helix No. 1 produces an inten- 
sity current, and from helix No. 2 to coil No. 
4A, a quantity current. 
88. If the ends of coil No. 2, as in the 
arrangement of Fig. 8, be united to helix 
No. 1 instead of coil No. 3, no shocks can be 
obtained ; the quantity current of coil No. 2, 
appears not to be of sufficient intensity to 
pass through the wire of the long helix. 
89. Also, no shocks can be obtained from 
the handles attached to helix No. 2, in the 
a coil No. 1, b coil No. 2, ¢ coil No, 3, d helix No. 1, e helix No. 2 and 3, f coil No. 4, and g magnetizing spiral. 
