COPPER SULFATE (cupric sulfate; blue vitriol; blue stone; blue copperas) CuSO4 · 5H2O Properties:  Blue crystals or blue, crystalline granules or powder; slowly efforescing in air; white when dehydrated; nauseous metallic taste.  Soluble in water, methanol; slightly soluble in alcohol and glycerol; d 2.284. Derivation:  Action of dilute sulfuric acid on copper or copper oxide (often as oxide ores) in large quantities with evaporation and crystallization. Method of purification:  Recrystallization. Grade:  Technical, CP, NF, also sold as monohydrate.  Available as crystals of powder. Use:  Agriculture (soil additive, pesticides, Bordeaux mixture), feed additive, germicides, textile mordant, leather industry, pigments, electric batteries, electroplated coatings, copper salts, reagent in analytical chemistry, medicine, wood and ground pulp, process engraving and lithography, ore flotation, petroleum industry, synthetic rubber, steel manufacture, treatment of natural asphalts.  The anhydrous salt is used as a dehydrating agent.