7 
4 
4 
4 
and Resistance of a Galvanic Circuit. 47 
' In computing these figures I made use of the values of col- 
umns (a), after having ‘raised objections against them. But it 
seems to me that I thereby did not unduly increase the results, 
attributing them as I do to the full difference of intensities, and 
to the difference of temperature as proceeding from the second 
intensity and the lowest. Considering this circumstance as 
chiefly affecting the results of columns (a), it appears also evi- 
dent that the increase of resistance within this column is not so 
much the result of difference of temperature, as of difference of 
intensity, since the influence of intensity starts from 1-982 in 
table vil, and 0°7844 in table vil, while. the influence of tem- 
perature starts in correspondence with intensity 1:8008 in table 
vu, and 0°6063 in table VIII. 
here is another circumstance connected with table vit, the 
internal resistance. If the noon a of this copper wire, — 
the true —— resistance are calculated separately, by m 
of combining the two first intensities with each of the Salles 
ones, there result values contained in columns (2) and (R). 
Both of them show the same ratio of increase as column (a), con- 
firming the fact as exhibited in table v. Thus ee the — 
of the 200 centimeters of copper wire to the —* istance 
proper, does not seem to modify the ratio of increase. 
he experiments for tables vit and VIII, still were rather un- 
satisfactory, showing rae great irregularities To avoid them, if 
e, and with a view to get a clue to the understanding of 
the matter, I cision tol another series of experiments, with as 
much care as I could afford, and the instruments at my command 
location of the tangent compass within coaak: 15 feet 
from an iron stove, and within about five feet distance from : 
* 
five pounds of iron which could not be removed. I therefore had 
to content myself with these results, and to use them with cau’ 
ition. 
In table 1x, the mean of the first three values of column (a) 
