INDUCTION SHOCKS 
rium construction is unimportant so long as secondary 
resistance is kept low. It is, however, of great impor- 
tance whenever the secondary resistance is high. 
The final series of comparisons was between coil B 
and the Porter inductorium, coil E. This yielded re- 
sults of the same sort as the preceding comparison, but 
more marked. Only with very low secondary resistances 
were Z B and Z E equal, and Z E became relatively more 
and more in excess of Z B as the secondary resistance was 
increased. Table XI illustrates this relationship very 
clearly. 
This last experiment brings out clearly the objection 
to the standard set by the Paris Congress of 1881 
TABLE XI 
Illustrating the Increasing Divergence of Z E from Z s with In- 
creasing Secondary Resistance 
Resistance in sec- 
ondary circuit. 
Z . 
ZE- 
Percentage 
variation of 
Z% from Z E . 
900 ohms 
15-75 
16.05 
1.9 
i, 600 ohms 
17.9 
19.8 
10.6 
2,700 ohms 
18.7 
26.8 
43-0 
8,600 ohms 
24.1 
46.0 
91.0 
20,600 ohms 
49.0 
135-0 
175-0 
(p. 89). The Porter indue toria conform closely to that 
standard in all respects save that of diameter of the coils. 
As Table XI shows, the influence of secondary resistance 
upon stimulating value is very much more marked in 
