Brown glass, circle based jar with plastic screw cap, sealed, and paper label, containing Diamorphine Hydrochloride B.P. powder. Manufactured by Thornton and Ross Limited. Diamorphine hydrochloride (heroin) is similar in action to morphine; it is a more potent analgesic than morphine but it has a shorter duration of action. It is used to treat severe pain in cases of advanced cancer when morphine in safe doses has proved inadequate. The jar dates from between 1969-1990.