In making these, distilled water should be used, and rather more of the colour than will fill the carboys made, to avoid the necessity of adding water to fill up after filtration, as this sometimes renders them turbid. The carboys should be perfectly clean, and also dry, or otherwise rinsed out with a portion of the filtered liquid.

1. Blues. Sulphate of copper 4 to 8 oz., water a gallon, oil of vitriol 1 oz.

2. Royal Blue. Sulphate of copper 8 oz., water a gallon; dissolve, and add water of ammonia till the full colour is developed; then water to make up 2 gallons.

3. Finest Royal Blue. Nitrate of copper 3 oz., water sufficient to dissolve it; add water of ammonia as long as the colour becomes deeper, then water to make up 2 gallons.

4. Paler. Crystallized acetate of copper 1/2 oz., hydrochloric acid 1 1/2 oz., water of ammonia q. s., water to make up 2 gallons.

5. Light Blue. Crystallized acetate of copper a scruple, water of ammonia 2 oz., water 2 gallons.