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Functions and ActivitiesThe functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the develop¬ ment and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structmes; advisory services to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Biu-eau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. PublicationsThe results of the Bureau's work take the form of either actual equipment and devices or published papers; these papers appear either ih the Bureau's own series of publications or in the journals of professional and scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing Office: The Journal of Research, which presents complete papers reporting technical investigations; the Technical News Bulletin, which presents smnmary and preliminary reports on work in progress; and Basic Radio Propa¬ gation Predictions, which provides data for determining the best frequencies to use for radio communications throughout the world. There are also five series of nonperiodical publications: The Applied Mathematics Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous Publications.

The Onsager theory of the static dielectri c constant of polar liquids has bee n modified to allow for t he influence of molecular shape. Equations have been derived for bot h prolate and oblate spheroids in which the permanent dipole is directed along t he axis of symmetry . These equations have beep applied to a number of pure polar liquids, exclusive of t he hydrogen bonded liquids, where reliable data were available over extended ranges of temperat ure. A satisfactory interpretation of the variation of dielectric constant with temperature is obtained provided the volume of t he molecular cavity is maintained fixed and independent of temperat ure rather than allowed to expand in proportion to t he molar volume a s assumed by Onsager. The required molecular shapes are in general accord with the actual molecular geom etries. The behavior of dilute solutions and mixt ures with a nonpolar solve nt are also satisfactorily correlated using the same shape parameters. It appears to he unnecessary to consider specifi c interactions betwee n neighboring molecules in order to accou nt for the static dielectri c behavior of t hese systems.

Conditions of applicability of the Ilkovic equation to polarographic analysis were investigated for representative ions singly and in mixtures. Gelatin was used to suppress maxima found in current-voltage curves.Results obtained with a capillary of usual characteristics showed that a suppresser is necessary to secure agreement with the llkovic equation over any considerable drop-time range, and that the need increases with the drop-rate of the electrode and the dilution of reducible ion. A criterion of diffusion control satisfactory for classification of polarograms by visual examination was found. The application of the Ilkovic equation to quantitative analysis was shown to be inadvisable unless it is definitely established that the experimental conditions are well within the range for insuring diffusion control. A logarithmic relation between critical drop-time and suppresser concentration was found.

A simple exten ion is presen ted of On sager ' elecLrostatie theory of di electric 1 olarization to take a ccount of t he "excess" polarization due to hyd rogen bOlldi ng. Dielectric data for a number of liquid mixtures arc analyzed and the d eviations from ideal be havior ex pressed in terms of an excess polarization. A method is d eveloped for calcula ting t he excess polarization and certain related molecular para meters. T e n tative value of these parameters have been d etermined for some particula rly simple structures.