PROFESSOR THOMSON ON THE ELECTRO-DYNAMIC QUALITIES OF METALS. 677 
After this experiment I considered it quite established that the Vitreous Electricity 
carries heat with it in copper. 
55. The conductor was still further diminished in breadth (so as to be only an inch 
broad in the parts between the heater and coolers on each side), and an experiment 
was made before my class on the 19th April, 1854, leading to the following results, 
shown as in the abridged tables of the preceding experiments. 
Experiment X. April 19th, 1854. 
Copper conductor of two slips, further diminished in breadth. 
(Current seven times six minutes each way.) Temperatures and 
differences of temperatures after six minutes of current entering 
Diminutions of 
differences from 
middles to ends of 
By end next A. 
By end next B. 
periods. 
Periods. 
Ta- 
Tb- 
Tb-Ta=D. 
T'a- 
Tb- 
Tb-Ta = D'. 
D-D'. 
I. 
74-30 
76-60 
2-30 
74-81 
77-50 
2-69 
-•39 
II. 
73-80 
76-48 
2-68 
75-32 
78-10 
2-78 
-•10 
III. 
76-25 
79-42 
3-17 
76-17 
79-18 
3-01 
•16 
IV. 
76-33 
79-51 
3-18 
76-28 
79-37 
3-09 
•09 
V. 
75-60 
78-69 
3-09 
75-20 
78-07 
2-87 
•22 
VI. 
74-80 
77-70 
2-90 
75-00 
77-75 
2-75 
•15 
VII. 
74-10 
76-84 
2-74 
75-42 
78-20 
2-78 
-•04 
Means, Period I. off ... 
75-147 
78-107 
2-96 
75-565 
78-445 
2-88 
•08 
Augmentation of differences during periods included... *09 
Add average augmentation per half-period *0075 
Add average augmentation per half-period *0075 
Effect due to reversal of current °*0875 
Means, Periods I. and 1 
VII. off / 
76-356 
78-36 
3-004 
75-594 
78-494 
2-90 
•104 
Augmentation of differences during periods included... -06 
Deduct average augmentation per half-period 
Effect due to reversal of current 
-006 
*110 
The effect here obtained, although of quite a decisive character, does not appear to 
show any increased sensibility resulting from the further diminution in the breadth 
of the conductor. 
56. The following Tables \^prmted after apart of § 58] show a complete analysis 
of the results of the seven experiments on the copper conductor which have been 
adduced. 
4 u 2 
