3386 H. Haug on the Electro-motive Force 
heated, thereby offer Jess resistance. The internal resistance 
being diminished, and measured with an increased unit, will, of 
course, appear smaller than at low intensities. But knowing this, 
every body ought to foresee the general increase of the constants 
of the galvanic current with the decrease of its intensity, instead 
of neglecting this fact entirely, or underrating its importance, 
and treating any variation of results simply as errors of observ- 
ation. 
whole, it is however just to remark, that it is indeed open to ob- 
jection on a general ground, since all the experiments, the ratio of 
increase of the resistance of conductors with increase of temper- 
ature, as commonly understood, is based upon, must have been 
influenced, and their results augmented, by any other reason of 
such increase of resistance, if there be any other reason at all. 
_But this interpretation of the fact in question is liable to more 
direct and more conclusive objections, and I could not feel sat- 
isfied with it at all. In the first place, there were the expert 
ments of table v, which seemed directly to contradict any such 
explanation. The ratio of increase of the internal resistance, the 
copper wire included, from 8°86 to 15-71 is oe 223718 
The ratio of increase of resistance of the copper wire, 
culated separately, from 4:0 to 7-1 is = 1:1775 
true internal resistance, resulting either by sub- 
tracting the resistances of the copper wire from the 
pective whole internal resistances, or by direct 
= 
calculation after the formula R=; a 2 : . increases 
from 4°86 to 8°61, or in the ratio of : = 1:17 
Thus the ratio of increase of resistance of the copper wire is the 
same as, or even a little greater than, that of the true internal re- 
o 
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