1105 
Glycollic acid and bromine. 
| Amount of | 
: ‘ | Time of | bromine | Unchanged : 
Quality of light. | exposure | added in Bromine Volume of solution 
grams 
a) Sunlight 22 | 0.06035 0.01234 | eere 
| | ! 10 
‚{ acid and 10c.c. bro- 
Darkness | 22’ | 0.06035 0.04218 |} mine water. 
b) Sunlight En: 0.00597 | 
| | Do 
Darkness 45 | Do 0.02242 
c) Diffused light 25° | Do 0.02234 | 
| Do 
Darkness | 25’ Do 0.04138 | | 
d) Diffused light | 50’ Do 0.01075 | 
| Do 
Darkness 50’ Do 0.02105 
Sodium glycollate and bromine. 
a) Sunlight 20’ (0.06035 | 0.00584 | 50 ce Ne 
| €. 50 
| collate and 10 c.c. bro- 
Darkness 20/ 0.06035 0.03345 mine water. 
b) Sunlight 50’ 0.12070 | 0.00052 || 59 le ere B 
A "7 10 
| collate and 20 c.c. bro- 
Darkness 50’ 0.12070 0.06375 |} mine water. 
c) Diffused light 55’ Do 0.02475 | 
| Do 
Darkness 55’ Do 0.06231 | | 
d) Diffused light 24’ 0.060385 | 0.01375 | | EDGE EN; sodium gly- 
| "10 
| collate and 10 c.c. bro- 
Darkness 24’ 0.06035 0.03205 |! mine water. 
From a glance at the foregoing tables it will be clear that the 
reaction velocity is greater with the salts than with the corresponding 
acids. Hence it can be inferred that the action of bromine takes 
place on the negative radicles (e.g. tartarate ions, oxalate ions ete.). 
It will be seen that oxalic acid and oxalates act most vigorously. 
Moreover it will be seen that in these actions the ‘Reciprocity 
Law” holds good; (i.e. a photo-chemical change will be in general 
greater the greater the intensity of light. If we denote by A — B 
