106
JOURNAL OF CHEMICAL EDUCATION -
JANUARY, 1931
Chemical Society, to the state departments of education and to the accrediting agencies for their serious consideration, with the hope that what has been presented may be of somz value in improving the status of science instruction in our schocls.
Literature Cited "How Are Teachers Being Trained in College for Teaching High-School Chemistry!" J. CHEM.EDUC.,5, 743-7 (June, 1928). "Curriculum Requirements in the Various States," ibid.. 6, 1156-7 (June. 1929). "The Training of Teachers of Chemistry in Secondary Schools in Some Foreign Countries," ibid., 7, 1363-6 (June, 1930). "Educational Requirements for Teachers of Chemistry in Secondary Schoals," ibid., 7, 2259 (Oct., 1930). "Professional Spirit among High-School Teachers of Chemistry, 111," ibid., 7, 1366-70 (June, 1930). Fxu~n,"Teaching First-Year Chemistry," fourth edition. J. 0 . Frank. Oshkosh, Wis., 1927, p. 7. H u s r o ~Educ. , Admin. Supnu., 9 , 4 2 3 3 8 (1923). EDIT., "Incompetence Guaranteed by Law," J. CHEM.EDUC.,7, 2221 (Oct.. 1930).
Propane as Liquid Gas Enters Isolated Kitchens. Liquefied propane, a new industrial gas preparation, is now available to country fuel-gas consumers who have no access to domestic gas lines. It is delivered under moderately high pressure, up t o ninety pounds, in portable steel tanks, ready fa connect to the kitchen stove. Propane is not new t o the laboratow. This is, however, probably the first time that a single chemical substance has been extracted from petroleum in liquid form for sale to the everyday retail fuel consumer. All other allied fuels, such as gasoline, benzine, kerosene, and the like are uncertain mixtures of a host of substances. For some years them has been a small trade in a very volatile mixed fuel extracted from "wet" natural gas. Such a product contains not only propane, which boils in its pure state a t 49 degrpes below zero Fahrenheit, but other substances of quite different boiling point, such as butane, boiling a t 33 degrees Fahrenheit, and pentane, 98 degrees Fahrenheit. When a polyglot fuel of this sort is allowed to escape from its domestic pressure tank into the kitchen stove, the propane part unfortunately comes out more rapidly than the other substances. Later, as the material is used up, the supply becomes mostly butane and pentane. These gases give too rich a mixture in the stove burner The flame tends to become sooty. Under the new system, the single substance, largely freed from impurities, is stored in the tank. The gaseous product comes uniformly throughout the full life of the tank charge. The manufacture of the aas is sumestive of the industrial preparation of pure . . . alcohol from a fermented solution, such as mash or molasses, by fractional distillation. In the ease of promme the boil in^.points of the materials are so low that the whole operation . . . has to he conducted under high pressure. It is then possible to condense the desired gas without recourse to expensive refrigeration.-Sciencc Service ~
