FEBRUARY, 1993
To the Editor: A letter in the November, 1952, issue by J. S. Miller, asks how one can predict the upper limit of swelling of
rnbber gloves in a solvent. There can be no exact answer to this question since the degree of swelling of vulcanized rnbber varies from one sample of rubber to another. Among the numerous factors affecting swelling are the per cent combined sulfur; the vulcanization accelerators and antioxidants; compounding ingredients such as carbon black, zinc oxide, and plasticizers; the degree of oxidation of the rubber hydrocarbon before, during, and after the manufacturing process; etc, etc. From the data given by Dr. Miller, I would hazard a
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prediction that in a few months time whatever antioQdent the gloves originally contained would have been leached out, oxidation would have reduced the molecular weight of the rubber hydrocarbon, and the rubber would have gone into colloidal solution.
To the Editor:
During the concluding session of the Conference of College Chemistry Teachers, held Friday and Saturday, November 14 and 15, on the Monmouth College campus, 90 representatives from 53 liberal arts colleges joined in the formation of a regional chemistry teachers association. The new group will be known as the Midwestern Association of Liberal Arts College Chemistry Teachers. Dr. Harry Lewis, Dean of The Institute of Paper Chemistry, invited the Association to meet next year a t Appleton, Wisconsin.
JOURNAL OF CHEMICAL EDUCATION
Members of the organizing committee include the following: Name J. B. Culbertsou D. W. Gier Edward L. Haenisch Fred Mathews Perry A. Moore Ben T. Shawver Gerrit Van Zyl
Imtitution Cornell College Park College Wabmh College Beloit College Hamline University Monmouth College Hope College
Representing Iowa Missouri Indiana Wisconsin Minnesota Illinoie Michigan
Edward L. Haenisch and Ben T. Shawver were elected as chairman and secretary, respectively. The following seem to have been among the factors which gave rise to the formation of the Association: (1) a widely shared feeling of satisfaction in the discussion of common teaching and administrative prohlems, and ( 2 ) the prior nonexistence of a regional organization serving to bring so many people interested in college chemistry teaching together.
