(5) LANCE,Z. phys. C h . , 168, 147 (1934); ibid., 177, 193 (1936). (6) LANGE AND HERRE,ibid., 181,329 (1938). (7) LONDON, Trans. Faraday Soc., 33, 8 (1937). (8) MCBAINAND BETZ,J. Am. Chcm. Soc., 57, 1905 (1935)
(9) ON~AOER, Physik. Z., 27, 388 (1926): ibid., 28, 277 (1927). (10) SCATCHARD, Chem. Revieus. 13, 7 (1933). (11) ULICH,Z. Elektrochem., 36,497 (1930); B R ~ L LGees. , chim. ilal.. 6 4 , 624 (1934); KIELLAND, I. Am. Chem. Soc., 59, 1675 (1937).
HIGH-SCHOOL NOTES ELBERT C. WEAVER' Bulkeley High School, Hartford, Connecticut SUGGESTION
I
N ORDER to visualize the idea of valence I supply
pupils with short lengths of copper wire and modeling clay of different colors. Using these materials, the pupils are required to construct simple models of compounds. Wads of clay represent atoms of elements and the wires the valence bonds. Each element has a separate color assigned. Within a short time pupils make satisfactory models of ternary compounds.DOROTHY G. HIMES, Polytechnic High School, Long Beach, California. INQUIRIES
H+. ., Ag+. Later on the following equation is given without explanation for the apparent contradiction.
How is this inconsistency best explained to high-school pupils?-E. C. WEAVER. Many elementary chemistry textbooks show diagrams of the experiment of the burning of dry hydrogen in air. The water formed is condensed in an uncooled inverted beaker or under a bell jar. The water formed is shown to run down into a vessel below where it collects in conriderable amount. In practice, the heat from the burning hydrogen warms this simple condenser to such an extent that only a little steam condenses to water. Are these diagrams unwarranted, or is some special technic needed to get amounts of water on such a condenser more than a mist?-E. C. WEAVER.
Why are the most active elements of the alkaline metal group . . a t the foot of Group I?-DOROTEY G. HIMES. Why can safety matches be ignited by scratching them on window ~ ~ ~ S ? - D O R O TG.RHXMES. Y In the electrolyk of alumina in fused cryolite by the POLICY Hall process is elementary fluorine first liberated? If so, does this in turn replace oxygen?-E. C. WEAVER. The sponsors of this column will be glad to carry Most elementary chemistry textbooks give the fol- supplementary material which will be helpful to highlowing order for electrochemical replacement: Kf. ., school teachers. We solicit questions, answers, helpful suggestions, items on educational advances, experi'Present address: Polytechnic High School. Long Beach, ments, local activity news, and requests for material. California.
SUMMER CONFERENCE OF THE NEW ENGLAND ASSOCIATION OF CHEMISTRY TEACHERS. PRELIMINARY ANNOUNCEMENT The first summer conference, held last August a t the Univer- wood Senior High School; Miss Eva Ruggli, of the Cambridge sity of Vermont, was so successful that the Executive Committee Latin School; and Mr. Theadore C. Sargent, of Swampscott of the New England Association of Chemistry Teachers has voted High School, Chairman. The followingofficers of the association to hold a second conference this summer. The meetings will he are also serving ex-officio:Mr. Ralph E. Keirstead, of Wethersheld on the campus of the University of Maine. Or0n0. Maine, on field High School, President; Professor Laurence S. Foster, of August 13, 14, 15, and 16, 1940. The morning and afternwn ~ and Mr. W . Davis Chase, of ~ University, ~ w Vice-president; n sessions will be devoted to topics of current interest pertaining to New Britain High School, A ~ , , ~ M,,neger , . ~ ~of the ~ ~Report ~ ~ the teaching of chemistry in secondary schools and colleges and N~~ ~~~~~~i~~ qf ,-hemislry ~ ~ ~ recent advances in scientific knowledge. Speakers of national There will be a fee of for in the asreputation will participate. Meals and lodging will be provided sociation who register before August Ist, and $3,00 for those who a t a very low rate by the University, and accommodations for register later than this date. Non-member teachers from New families will be available. A social program, taking advantage of the location of the conference at one of the country~sforemost England. or elsewhere, who wish to attend, may do so by paying the usual membership fees of $3.00 far a full membership and vacation spots, is being planned. $1.50 for an associate membership. Payment of a registration of the following: D ~ , ~h~ committee in charge is of the immediate family of L~~~~~~~H. ~ ~of the university ~ f, ~ comecticut; d pro. ~fee will not ~ be required ~ of members , fessor Avery Ashdown, of the Massachusetts Institute of Tech- teachers attending the conference. For further information, a letter should be sent t o Mr. Theonology; Professor Charles A. Brautlecht, of the University of Maine; Mr. Roscoe Dake, of Phillips Academy; Mr. Standish dore C. Sargent, 834 Humphrey Street. Swampscott. MassaDeake, of Milton Academy; Mr. Everett F. Learnard, of Nor- chusetts.
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