78 
MESSRS. W. DE LA RUE AND H. W. MULLER ON THE 
instances is in a great measure to be attributed to more rod-cells being employed in 
some of the experiments, as these offer less internal resistance than powder-cells. 
Hydrogen.— Discs distant 0'2‘2 inch = 5’588 m.m. 
IV. Temp. 15 0, 6 C. 
V. 
Temp. 12°-7 C. 
VI. Temp. 10 
°-2 C. 
Cell?. 
Pressure. 
Current. 
Cells. 
Pressure. 
Cells. 
Pressure. 
m.m. 
M. 
W. 
m.m. 
M. 
m.m. 
M. 
10,980 
760-6 
1,000,789 
0-03071 
1-0980 
759 7 
999,605 
10,980 
751-0 
988,158 
9780 
671-8 
883,947 
0-02881 
9780 
658-9 
866,974 
9780 
661-0 
869,737 
8580 
564-6 
742,895 
0-02881 
8580 
559'6 
736,316 
8580 
576-5 
i o 8, o o 3 
7380 
472-3 
621,447 
0-02881 
7380 
483-8 
636,579 
7380 
466"5 
613,816 
6180 
400-6 
527,105 
0-02693 
6180 
395-0 
519,737 
6180 
387-6 
510,000 
4680 
271-9 
357,763 
0-01772 
4680 
272-8 
358,947 
4680 
258"5 
340,132 
3220 
160-1 
210,658 
0-03259 
3220- 
173-5 
228,289 
3220 
164-6 
216,579 
2140 
97-4 
128,158 
0-02505 
2140 
98-1 
129,079 
2140 
93-6 
123,158 
1060 
37-0 
48,684 
0-02136 
1060 
37-8 
49,737 
1080 
38-6 
50,789 
600 
13-9 
18,289 
0-05801 
600 
15*4 
20,263 
600 
12-5 
16,447 
Carbonic Acid. —Discs distant 0'122 inch = 3‘096 m.m. 
VII. Temp. 12°'2 C. 
VIII. Temp. 14°"5 C. 
IX. Temp. ll°-6 C. 
Cells. 
Pressure. 
Cells. 
Pressure. Cells. 
Pressure. 
10,960 
9880 
8800 
7720 
6300 
4800 
3600 
2400 
1200 
m.m. 
757-9 
693-0 
602-2 
492-4 
370-7 
277-9 
186-0 
104-2 
31-3 
M. 
997,237 
911,842 
792,368 
647,894 
487,763 
365,658 
244,737 
137.105 
41,184 
10,960 
9880 
8800 
7720 
6300 
4800 
3600 
2400 
1200 
600 
m.m. 
747-2 
647"5 
576-7 
485-9 
383-2 
249-4 
177-7 
95-8 
30-0 
5-1 
M. 
983.158 
851,974 
758.816 
639,342 
504,211 
328.158 
233.816 
126,052 
39,474 
6,710 
10,960 
9880 
8800 
7720 
6300 
4800 
3600 
2400 
1200 
600 
m.m. 
747-6 
676-7 
583-9 
505-1 
393-3 
258-6 
183-8 
94-9 
30-0 
5-3 
M. 
983,684 
890,395 
774.868 
664,605 
517,500 
340,263 
241,842 
124.868 
39,474 
6974 
The numbers obtained for ah', hydrogen, and carbonic acid respectively were plotted 
down on millimetre scale paper, the abscissae being 1 m.m. = 2500 M, the ordinates 
1 m.m. = 25 cells, and curves drawn to give a mean of the several observations. 
These appeared to resemble hyperbolic curves so closely that true hyperbolic curves 
were found (partly by a geometric construction/" partly by computation) which would 
intersect the mean experimental curves in two points. The results of experiment 
* The following, suggested to us by Professor Stokes, is the convenient method employed. The experi¬ 
mental curve is laid down on squared paper, as shown by the dotted line in fig. 75", and two points, g' and 
h!, for the intersection of the proposed hyperbola are selected, and two corresponding points g, h at the 
same distances respectively on the opposite side of the vertical axis are marked; through g' and h and 
through g and h 1 lines are drawn intersecting in A, lines are also drawn through li and g', and h and g 
intersecting in B; a line is drawn through A and B and prolonged on each side in the direction of the 
axis. The distances of VB and YA are ascertained in terms of the squared paper, their reciprocals taken 
