14 Messrs. Wright and Thompson on the Determination of 
increase as the value of m diminishes, 7. e. as the mixed solution 
is weaker so far as the copper sulphate contained is concerned. 
This is in fact the case, as shown by the following Table, 
representing the H.M.F.’s of such pairs of cells uniformly 
containing amalgamated-zine and electro-copper plates, the 
former immersed in m ZnSO, 100 H,O; the E.M.F.’s of the 
cells containing m CuSO,, n ZnSO, 100 H,O are derived 
from the preceding tables, and those of the cells containing 
(m+n)CuSQ, 100 HO are calculated by means of the for- 
mula H=1114+a, in which 1114 is the constant H.M.F. 
in millivolts of an ordinary Daniell cell containing m MSO, 
100 H,O, where m is constant for both zinc- and copper-sul- 
phate solutions (§ 170, footnote), whilst a is derived from the 
table given in Part VIII. § 154. 
E.M.F. of cells containing 
m. aor ee a ce ee 
(m+n)CuSO, | mCuSO,, » ZnSO, | ence.| m 
100 H,0. 100 H,0. 
Merit ie nes) 1116-9 11140 29 | -28 
1-42 | 5 1116-9 1112°6 4°3 339) 
1-42 | 10 1120°2 1112-0 8-2 “70 
1:00 | 25 1115-6 11133 2°3 "25 
100 | °d 1117-2 11126 4-6 ‘50 
1:00 | 1:0 1120°4 1111-7 87 | 1:0 
1:00 | 15 1123°4. 1111-0 12:47 
5 ‘1 1114-9 11136 1:3 2 
5 "25 11163 1113°3 3:0 yo 
9) 5 1118-6 11126 6:0 | 1:0 
5 10 1121°8 1111-5 10°3 | 2:0 
D 1°5 1125-0 1110°7 14:3 | 30 
5 -| 2:0 1128-0 1110-0 18:0 | 4:0 
"25 | °25 1119°6 1113-1 65 | 1:0 
20:1 "1:0 1125°8 1111-4 144 | 40 
25 | 2:0 1132-1 1109-9 22°2 | 8-0 
Fig. 3 represents these numbers, the values of — being the 
abscissze and those of the “differences ’”’ the ordinates of the 
curves drawn, which are evidently such that the curve where 
m has the highest value overlies the others; and similarly 
throughout. 
