1336 
thein. One of tliem was exposed to bright snnlight on clear days at 
12 in the noon, the other covered with a piece of black flannel and 
was placed bj Ihe side of the other. Aftei* one hour’s exposure the 
amoiint of residnal iodine was titrated against Standard thiosulphate. 
In the foiir following observations, in order to exclnde air a 
cnrrent of nitrogen was passed throiigh the solntion and the bottles 
were stoppered and exposed at 12 in the noon as usnal. 
Light 
60' 
0.0635 
0.00012 
Darkness 
60' 
Do 
0.05180 
Light 
60' 
Do 
0.00011 
Darkness 
60' 
Do 
0.05176 
Light 
60' 
Do 
0.00010 
Darkness 
60' 
Do 
0.05177 
Light 
60' 
Do 
0.00012 
Darkness 
60' 
Do 
0.05178 
In the four following observations a cnrrent of carbon dioxide 
was passed throngh the mixture and therebj oxjgen was excluded 
and the effect of carbon dioxide conld be observed. 
1 ) 
2) 
3) 
4) 
Light 
60' 
0.0635 
0.00011 
Darkness 
60' 
0.0635 
0.05176 
Light 
60' 
Do 
0.00012 
Darkness 
60' 
Do 
0.05175 
Light 
60' 
Do 
0.00010 
Darkness 
60' 
Do 
0.05180 
Light 
60' 
Do 
0.00012 
Darkness 
60' 
Do 
0.05178 
Evidentlj oxj’gen and carbon dioxide are without any inflnence 
on the actinometer. 
Now the effect of diffnsed day-light was observed. The bottles 
were put in a shady place on bright snnnj days. 
