224 Dr. F. Aucrbacli on the Passage of 



determination of a + b\ w and w f the corresponding true resist- 

 ances; r denotes "right," I "left." 



7. Wire/ 10 . From 1 to 6 Daniell elements. ic=103'9. 



n. 



a+b. 



s. 



s'. 



io. 



w'. 



Mean. 



1 



4-6 



, 0*5 r 



0-5 r 



103-889 



103-S89 



103-889 



o 



S-o 



01 



o-i 



899 



899 



899 



o 



O 



122 



101 



101 



908 



908 



908 



4 



15-2 



2-3 



2-9 



915 



919 



917 



5 



176 



6-0 



61 



934 



935 



934 



6 



200 



9-8 



10-1 



949 



950 



950 



- 1 = g 12 = 0'00010. 



Of the differences ic n — w n _i the first are constant — namely, 

 10, 9, and 9 respectively; the last two, on the contrary, are 

 greater, namely 17 and 16: these latter point to thermal in- 

 fluences. These are in general easily recognizable in that 

 they increase with n, while the influence in question here must 

 diminish with n (on account of the gradual saturation of the 

 wire). 



8. Annealed iron wire f n . Z=43200, eZ=O205, w=182*6. 



n. 



a+b. 



5, 



s'. 



w. 



ic'. 



Mean. Difference. 



1 



1-6 



06 1 



0-8/ 



182-638 



182-650 



182644 ~ 

 r .- n 26 

 670 r 



2 



2-9 



19 



2-2 



665 



676 



3 



4-4 



3-1 



3-6 



668 



682 



675 o 

 678 t g 

 687 ° 

 702 lo 



4 



5-8 



4-0 



5-1 



669 



687 



5 



7-1 



5-6 



6-7 



679 



694 



6 



8-3 



8-2 



8-7 



699 



705 



The influence of the heating is here still more clearly di- 

 stinguishable from that of the intensity of the current. The 

 latter gives 



S 14 = 0'00019. 



Hence we get S 12 = 0*00014:. With the hard wire / 10 the 

 decrease of the quantities ic 2 — u'i, w B —w 2 , &c. was very slow. 

 There, at all events, the influence of the current-intensity far 

 exceeds rc=4. But there S 14 =0*00028, while a i2 = 0'00010. 

 Therefore the dependence of the resistance on the intensity of the 

 current is greater there than here; while here 8 12 is greater, i. e. 

 the dependence is concentrated upon a smaller region. If we 

 imagine curves constructed for both cases, the abscissae repre- 

 senting the current-intensities .r, the ordinates the resistances 



