A highly accurate and efficient syringe with a valve in a housing has a hollow syringe with a barrel and a hollow tip, a port on the side of the barrel near the hollow tip, and a valve connected to the barrel by the housing, which has a mouth connected to the barrel and a bottle cap suitable for securing to a bottle. The valve is in fluid communication with the barrel through the port and in fluid communication with a bottle of chemicals through the bottle cap end of the housing. The syringe with a valve in a housing is adapted to precisely draw and measure chemicals from a bottle and to precisely dispense the chemicals without spills or drips.