Made from heavy moulded borosilicate glass, all joints are interchangeable. A rapid and effective apparatus to produce controllable amount of common gasses such as hydrogen sulphide, carbon dioxide etc. Comprising of three chambers, a lower acid reservoir with glass stopper, a central bulb to which stopcock is fitted, an upper bulb with a tapered tube extending downwards into the reservoir and a safety  funnel. A separator prevents the solid reactant in the central bulb from falling  into the reservoir.