Nuclear magnetic resonance absorption line widths have been studied for several high polymers. The proton line widths were studied in a field of 7000 gauss and at a frequency of about 30 mc. Line widths obtained for Hevea and GR-S were very narrow, indicating a large degree of ``quasi-free rotation'' in these materials. Vulcanization, carbon loading, co-polymerization, and crystallization produced a broadening of the lines as expected from the hindrance to internal motion introduced by these factors. Line width transitions as a function of temperature were observed for several polymers. Linear thermal expansion coefficients and specific heat vs temperature curves have breaks in the region of line transitions for the polymers studied. Swelling of polymers with benzene produced a narrowing of the absorption line throughout the line transition and lowered the transition temperature. Vulcanization broadened the transition range and shifted it to higher temperatures. Of two closely cut fractions of polystyrene, the larger molecular weight sample exhibited a line transition range at a higher temperature. The styrene monomer as well as the two fractions exhibited the same low temperature line width of about 8 gauss. The line width transitions were also studied for three butadiene styrene co-polymers at temperatures where anomalous behavior was found in dynamic measurements. The theoretical implications of these experimental results, together with a survey of other pertinent work, indicate the possibilities of the nuclear resonance method as applied to the study of high polymers in conjunction with other methods.

The linear thermal expansion coefficients of the a and c axes of bismuth have been measured from 80°K to 540°K by mechanical means. These same coefficients were determined over a more limited range of temperatures by single crystal and powder x-ray methods. The mechanical and x-ray values did not differ significantly. The expansion coefficient for the c axis was found to be 16.6±0.4×10−6 (C°)−1 at 100°K, 17.3±0.2×10−6 (C°)−1 at 150°K, and 17.6±0.2×10−6 (C°)−1 at 540°K. For the a axis the expansion coefficient was 10.8±0.3×10−6 (C°)−1 at 100°K, 11.6±0.2×10−6 (C°)−1 at 150°K, and 11.8±0.2×10−6 (C°)−1 at 540°K.

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The optical spectrum of the weak luminescence produced when water is irradiated by an intense ultrasonic beam has been determined. Water saturated with argon, helium, oxygen, or nitrogen was studied with the use of 800-kc radiation. The spectral distribution of the luminescence was measured with a spectrometer and photon counter combination in the interval 2800-5500 A. The spectra are continuous and correspond to that of a blackbody. For dissolved argon and helium the equivalent temperature is 11 OOooK, whereas for dissolved oxygen and nitrogen the temperature is 8800 o K.

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