1428
JOURNAL OF CHEMICAL EDUCATION
NOVEMBER, 1928
A CONVENIENT FORM OF HYDROGEN SULFIDE GENERATOR An eight- or ten-inch ignition tube will serve best for a generator. Grind a small hole about one-sixteenth of an inch in diameter in the end of the tube. A small piece of glass will answer the purpose for a surface upon which to grind the tube. Introduce a few large pieces of ferrous sulfide into tube the generator and attach a suitable deRubber stopper livery tube to it. In order to set the generator in operation place the tube with its iron sulfide Test tube into a rather tall narrow container which has some dilute hydrochloric acid in it. A graduate just a little larger than the Test tube clamp generator is very satisfactory. If the delivery tube is k d e r the surface of the solution into which it is conveying the Acid 'Ontainer gas there will be a little hack pressure in the generator. This will cause the level of the acid in the outside container to rise so that there may be danger of its Iron sulfide running over the top. After afew trials one can easily estimate the proper Hole in test tube amount of acid to use. When the Dilute acid generator is not in use it can he raised up out of the acid and clamped in place with a test-tube holder. This allows the acid to drain out and thereaction stops. OP GENERATOR WHENNOT POSITION The writer has found this type of m USE generator very economical in acid consumption. The student also seems to accept it veryreadily for his laboratory work, especially in the experiments in qualitative analysis. Three such tubes for hydrogen, carbon dioxide, and hydrogen sulfide, respectively, kept in the teacher's private laboratory, will be found to conserve his time.
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