The sketch illustrates a gas generator designed for laboratories where gases are needed in large quantities and frequently. The shelf holding the large inverted bottle is of thick wood, and to reinforce the whole apparatus, a 1-in. copper strip is placed around the bottle tightly and fastened with screws turned into the woodwork. The shelf above is attached last, and upon it rests the bottle of commercial acid required in the gas generation. The pump shown is for use in starting the siphon.

Gas Generator of Large Capacity That will Work Automatically as the Gas is Removed

Ill: Gas Generator of Large Capacity That will Work Automatically as the Gas is Removed

The large bottle used as a generator may be either a 3 or 5-gal. size, and after it is placed in the position shown, a sufficient amount of the solid reagent needed in gas generating is placed in the mouth before the exit tube, leading away below, is fixed in position. If sulphureted hydrogen is required, ferrous sulphide is used; if hydrogen is required, zinc is placed within; and to make a carbon dioxide, marble, or Its equivalent, is inserted. Whatever gas is required, a sufficient quantity of the solid material is put in to last for some time in order not to disturb the fastenings.

When all is ready, the pump is used gently to start the acid over the siphon and into the generator from below. The gas generated by the action of the acid on the solid soon fills the bottle. The screw clamp on the exit tube is loosened and the gas passes into the bottle of water and charges it, in the case when sulphureted hydrogen is required. In the other cases, when sufficient gas has been generated, the screw clamp is tightened, and the gas soon attains considerable pressure which forces the acid back out of the generator and into the acid bottle above. The whole apparatus now comes to an equilibrium, and the gas in the generator is ready for another use. - Contributed by W. M. Mills, Bakersfield, Cal.