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V O L U M E 22, NO. 4, A P R I L 1 9 5 0 amide and of Nylon 6B in a 10“ .If 85/15 ethyl alcohol-water solution, were compared with the spectra of adipamide, malonamide, and pelargonamide in crystalline form or in water or alcohol solutions. The amide solutions had been heat-treated to impose the two types of association of amides through hydrogen bridges which result from fast or slow cooling and exhibit distinctive absorption spectra ( 2 ) . The short wavelength continuum which appears in the spectra of these molecules has been attributed to the dissociation of the hydrogen-bridged bonds following electronic excitation (1). The spectra of the nylon films resemble those of slowly cooled amides, and that of the K’ylon 6B solut’ion the spectra of rapidly cooled amides, the former being long linear polymers, the latter dimers or polymers with only a few members, in which the hydrogen bridges bctween units are ruptured by the absorption. (1) Anslow, Hsieh, and Shea, J . Chem. Phus., 17, 426 (1949). (2) .%nslow-, G. A , and Shea, R . C., Phys. Rer., 75, 1318 (1949).
Spectrochemical Methods of Brass Analysis. M. F. HASLER C. E. HARVEY, Applied Research Laboratories.
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TKOanalytical techniques were discussed: a point-to-plaiic procedure suitable for the rapid routine analysis of metal specimens, and a solution method that permits the validation of standards. The latter also offers an alternative method for control analysis under some circumstances. Certain fundamental problems were discussed from the standpoint of the above procedures: the interrelation of metallurgical variables and discharge conditions; other related variahles; the synthesis of standards; quantitative calculations in varying t,wo and three major constituent systems; comparison of photographic and quantonietric recording. A Curve Computer. I!E. . I ~ O W LMIDDLETOS, EY Sational Rescarch Council of Canada.
An instrument has been designed arid constructed for the purpose of multiplying, dividing, adding, or subtracting the ordinates of t’woCartesian curves, and plotting the result. The principle is that of the \!-heatstone net, balanced automatically by means of a scrvo system. Certain logarithmic operations can also be performed, and L: planimeter attachment integrates thc area under the curve representing t,he product, etc. The overall accuracy is about 0.3%. The curve computer has many applications in photometry and colorimetry, such as the conversion of filters from one thickness to another, and the coniputation of tristimulus values,
and glossy sides of all chips on a G.E. recording spectrophotometer. Tristimulus specifications or I.C.I. illuminant C were obtained a t the same time from an automatic, continuous tristimulus integrator ( 1 ) attached to the spectrophotometer. Representative portions of these data were presented, and a comparison made with the corresponding data (2) of the earlier edition of chips. (1) Davidson, H. R., and Imm, L. IT.,J . Optical SOC.Am., 39, 633 (1949). (2) Granville, W.C., and Jacobson, E., Ibid., 34, No. 7 (1944). (3) Jacobson, Egbert, “Color Harmony Manual,” Container Corp of America, Chicago, 1942 and 1946. (4) Jacobson, Granville, and Foss, Ibid., 1948.
Application of the Hunter Color-Difference Meter to a Tomato Color Measurement Problem. S. G. YOUNKIN, Campbell Soup Company. In the present study, a Huuter color-difference meter \vas used to obtain color specifications of tomato purees, and for the first time i t has been possible in our laboratories to make rapid, repeatable, small color-difference measurements. porcelain-enamel reference standard having color specifications similar to tomato purees was used to obtain values of Hunter’s I,, U L , and b L by viewing 130 ml. of each uree through the base of a specially constructed glass cell. Varues of a~ and bL were plotted on a chromaticity diagram with L values designated numerically for each plotted point. Munsell renotation loci for hue and chroma were placed on these diagrams for orientation purposes. Visual examinations were made of purees contained in square glass bottles. Samples were viewed by daylight and scored on the basis of appearance. Altogether there were several thousand purees prepared from fruits grown a t widely separated points, under different environmental conditions, and harvested a t different degrees of maturity. Essentially a perfect correlation was obtained between color-difference meter specifications and visual scores regardless of the magnitude of volar differences.
Officers of Division of Analytical Chemistry
The Nominations Committee of the Division of Analytical Chemistry requests the cooperation of the members of the division in suggesting names of members for nomination to the offices of chairman-elect, secretary-treasurer, councilor, and alternate New Automatic Colorimeter for Cotton. DOROTHY SICKERSOS, councilor. The committee is to present two nominees for each I,-.s. Department of Agriculture, A N D RICHARD s. HUSTER.ASD 1I.IRSHALL G. POWELL, H. A. Gardner Laboratory, Inc. office. The nominations are for offices to be filled for the year 1951, for which elections will be held a t the fall 1950 meeting of This instrument is based on a satisfactory application of ttw the Society. Suggestions should be sent to the Chairman of the Huntcr color and color-difference meter ( 1 ) to problems of ra\v cotton measurement. For cotton colors Hunter’s coordinat,es Nominations Committee, William Seaman, American Cyanamid Rd and b provide, without conversion, a picture close to that of Company, Calco Chemical Division, Bound Brook, ?;. J. measurements in terms of Munsell valuc and chroma. Thewfore an instrument was designed to be fully automatic arid selfstandardizing, and graphically to show on a two-dimensional scale simultaneous values for reflectance and yellowness. Furthermore, the instrument is self-contained in a movable cabinet about table height, with a minimum of esposed parts, and working parts in the horizontal plane of the table. Electrical iiieaSurenients of photocell current,s are converted to color as in thc color-difference meter, escept that Brown Electronik amplifier; replace the galvanometer, and reversible motors responding to the signals from these amplifiers replace the human operator, both in st,sndardizing the instrument and in turning dials to obtain color settings. Although this particular instrument, is limited to tjhe range of cotton colors, the principles upon which Scientific Apparatus Makers of America. Chicago. Ill,. May it is designed :&readaptable to other limitcd ranges of color, i n 18 to 20 either two or three dimensions. Society for Applied Spectroscopy. Xew York, N. Y..May 26
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(1) Hiintrt.. R. S., J . Optical SOC.Am., 38, OG1.4 (1948).
Color Harmony Manual. U‘ALTERC. Corp. of .4merica, Chicago, Ill., CARLE. AND I. H. GODLOVE,General -4niline Easton, Pa. The third edition (4)of the “Color Harmony Manual” reprcsents a complete revision of the earlier editions ( 3 ) and includes 263 colors in addition to the 680 in the regular abridgment of t’he Ostwald system of color organization. The new edition was shown and the basis for the revision disrussed. Spectrophotometric measurements have been made for both the mattc
and 27 Symposium on Molecular Structure and Spectroscopy. Mendenhall Laboratory of Physics, Ohio State University, Columbus, Ohio, June 12 to 17 Third Annual Summer Symposium. Ohio State University, Columbus, Ohio, June 16 to 17 International Microchemical Congress. Graz, -Austria, July 2 to 6 Instrument Conference and Exhibit. Instrument Society of America, Buffalo, ?;. T., September 18 to 22
