REVERSIBLE AND IRREVERSIBLE SYSTEMS UNDER INFLUENCE OF LIGHT. 401 
Average 
amperes 
observed 
in 
10" 9 
units. 
Average 
volts 
observed 
in 
ltr 6 
units. 
Calibration 
of 
Nalder Nl, 
in 
centimetres 
(right 
and left). 
Calibration 
of 
Nalder N2, 
in 
centimetres 
(right 
and left). 
Distance 
of 
light from 
quartz 
vessel, in 
centi¬ 
metres. 
Distance 
of 
light 
from 
Rubens 
thermo¬ 
pile, 
in 
centi¬ 
metres. 
Intensity 
of light 
measured 
with 
Rubens 
thermopile 
at the 
distance 
given 
to Column 
XVI., in 
millimetres 
(right 
and left). 
Tempe¬ 
rature of 
bath, 
in ° C. 
Temperature 
of room, 
in ° C. 
Kind of cell. 
¥ 
Kind of 
light used. 
Volts and amperes when 
arc was used. 
Photo¬ 
graphic l 
plate 
number. 
XI. 
XII. 
XIII. 
XIV. 
XV. 
XVI. 
XVII. 
XVIII. 
XIX. 
XX. 
XXI. 
XXII. 
Illuminated and not Illuminated parts of the Solution. 
Hg, solid HgoBi'o in Decinormal NaBr and KBr Solutions. 
lb ’0 
16 -0 
88 
123 
46, 7 
18 • 7 ordinary 
temperature 
total light 
acetylene 
22 
16-0 
16-0 
88 
123 
46, 7 
18 -7 ditto 
total light 
acetylene 
_ 
— 
16*0 
16 -2 
88 
123 
46, 7 
18 - 7 ditto 
total light 
acetylene 
1(3*0 
16-2 
88 
123 
46, 7 
18 ‘7 ditto 
- 
total light 
acetylene 
— 
— 
16 *0 
16-8 
118 and 47 
- 
98 
ordinary temperature 
— 
total light 
arc 
21 
— 
— 
16*0 
16-8 
47 
— 
98 
1 
ordinary temperature 
— 
j total light 
arc 
Hg, solid S0 4 Hg 2 in Soluble Sulphates, S0 4 (NH 4 )2, &c. 
since Hgolo is Decomposed by KI already in the Dark. 
— 
16*0 
16 *85 
30 
98 
98 
ordinary temperature 
constant 
total light 
arc: 65 volts, 6 "1 amperes 
23 
— 
16*0 
16*85 
30 
98 
98 
ordinary temperature 
constant 
red screen 
arc: 65 volts, 6 -1 ampSres 
deflections obtained with Nalder N2, when the light was removed from Rubens thermopile, by the distance given m 
Column XIV. (with a Clark, 100,000 ohms, inserted, and shunt of galv. = 10 ohms.). 
shunt of galvanometer. _ _ 
1 eentim. Different heights of mercury give different values. The E.M.F. is principally a thermo E.M.F. 
3 F 
YOL. CCVI.-A. 
