| Bulk | 50.0 c.c. | 100.0 c.c. | 200.0 c.c. | 300.0 c.c. |
| "Uranium" required | 14.0 " | 14.0 " | 14.5 " | 15.0 " |
Considerable variations in bulk are to be avoided.
Effect of Varying Sodium Acetate.—These experiments were carried out like those last noticed, but the bulk was 150 c.c., and varying amounts of sodic acetate were added in excess of the quantity used in the experiments previously described:—
| Sodic acetate added | 0 gram | 1 gram | 10 grams | 20 grams |
| "Uranium" required | 14.5 c.c. | 14.5 c.c. | 16.0 c.c. | 18.0 c.c. |
It is evidently important that the quantity of this salt present in each titration be measured out, so as to avoid variation.
Effect of Varying the Sodium Acetate and Acetic Acid Solution.—Acetic Acid also affects the results, but in the opposite direction, by preventing the precipitation of uranium arsenate. With varying volumes of the solution now under notice, the results were:—
| Solution added | 0.0 c.c. | 5.0 c.c. | 10.0 c.c. | 15.0 c.c. |
| "Uranium" required | 14.5 " | 14.5 " | 14.5 " | 14.0 " |
| Solution added | 20.0 " | 30.0 " | 40.0 " | 50.0 " |
| "Uranium" required | 13.2 " | 10.0 " | 6.0 " | 2.0 " |
These show that the quantity ordered (5 c.c.) must be adhered to.
Effect of Foreign Salts.—In these experiments, 10 grams of the salt (the effect of which it was desired to determine) were added to a solution in other respects resembling those previously used:—
| Salt added | Ammonic sulphate | Ammonic nitrate | Ammonic chloride | Magnesium sulphate |
| "Uranium" required | 15.5 c.c. | 15.5 c.c. | 15.3 c.c. | 15.3 c.c. |