SIMPLE GAS GENERATOR D. IRVINE WALKER Gn'nnell College, Grinnell, Iowa
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N RECOGNITION of the need for a compact, efficient, and inexpensive gas generator to be used by the individual a t the laboratory desk or by the instructor a t the lecture desk, I offer the following specifications for one that complies with these standards. It may be used for generating C02,HzS,H*, CzH2,etc. The generator may be made in a few minutes. The bottom of a ' / s w test-tube ( C ) is perforated and two holes are made in the sides, one about one-third and the other about two-thirds of the way from the bottom (x and y ) . This tube is fitted with a one-hole rubber stopper containing a right-angle tube, preferably fitted with a stopcock. The end is cut off a 1"test-tube ( B ) . This is also fitted with a rubber stopper having a hole into which the test-tube ( C )fits tightly. The whole of this apparatus ( B and C) is fitted into a wide-mouthed bottle with a rubber stopper having an additional small hole for the purpose of admitting air. To charge the apparatus, the acid or liquid used is
placed in the wide-mouthed b o t t l e ( A ) so t h a t i t comes just above the hole (y). The small test-tube ( C ) is then taken out and charged with the metal or compound necessary for the evolution of the desired gas. When the stopcock is opened the acid or liquid rises in ( B ) and (C) and reacts with the substance in (C) to generate the gas. When the stopcock is closed, the gas continues to evolve until the pressure developed forces the liquid below (C) in (B).
