| Water added | none | 100 c.c. | 200 c.c. | 400 c.c. |
| Silver required | 47.0 c.c. | 47.0 c.c. | 47.0 c.c. | 47.05 c.c. |
Very considerable dilution therefore has no effect.
Effect of varying soda.—The conditions were those of the 40 c.c. experiment in the first series, except that varying amounts of soda solution were used.
| Soda added | none | 10 c.c. | 30 c.c. |
| Silver required | 46.95 c.c. | 47.0 c.c. | 47.0 c.c. |
This alkali therefore has no prejudicial effect.
Effect of ammonia.—Soda causes turbidity in some cyanide liquors; with these it should be replaced by 2 or 3 c.c. of dilute ammonia with a gram or so of ammonium chloride. The following experiments with dilute ammonia show that larger quantities of this reagent must be avoided.
| Ammonia added | none | 10 c.c. | 30 c.c. | 60 c.c. |
| Silver required | 46.95 c.c. | 47.15 c.c. | 47.7 c.c. | 49.5 c.c. |
Effect of sodium bicarbonate.—In this experiment 1 gram of bicarbonate of soda was used instead of the soda or ammonia of the other experiments. The silver nitrate required was only 46.45 c.c. instead of the 47.0 c.c. which is the normal result. This is probably due to the liberation of prussic acid and shows the importance of having the solution alkaline.
Effect of zinc.—In each experiment 40 c.c. of the cyanide solution and .5 gram of zinc sulphate crystals were used and the bulk was made up to 100 c.c. before titrating.
| Soda added | 1 c.c. | 5 c.c. | 10 c.c. | 25 c.c. |
| Silver required | 47.1 c.c. | 47.0 c.c. | 46.9 c.c. | 46.9 c.c. |