Copper sulfate, also known as Lan, Chemical type CuSO4, no water for white powder, water is blue powder, or because of impure and grayish green, is soluble copper salt. The common form of copper sulfate is its crystal, one hydrated copper hydrate ([Cu (H2O) 4]so4 H2O, hydrated copper sulfate), is a blue solid. The water solution is blue due to the hydration of copper ions, so anhydrous copper sulfate in the laboratory is often used to test the presence of water. In the actual production life, copper sulfate is often used to refine copper, mixed with hydrated lime for to produce the pesticide Bordeaux liquid. Copper sulfate belongs to heavy metal salt, poisonous, adult lethal dosage 0.9g/kg. If swallowed, should be immediately large consumption or drink milk, egg clear, such as rich in protein food, or use EDTA calcium sodium salt detoxification. White anhydrous copper sulfate powder drops into the water after the blue