This is made by dissolving 2 lb. copper sulphate in 6 to 8 gal. of water in an earthen or wooden vessel, and then adding 1 qt. of ammonia and mixing with 50 to 60 gal. water.

Modified "Eau Celeste" is made by dissolving 4 lb. copper sulphate in 10 to 12 gal. water, and stirring in 5 lb. of washing soda. Dissolve 1 1/4 lb. of soda in hot water; then add 3 pt. of ammonia, and dilute to 50 gal. of water. (See "Ammoniacal Copper Fungicide").