Hoover for the and Dr. C. L. toglobulin containing two equivalents of firmly bound dodecyl sulfate is described. The solubility, mobility, titration curve and denaturation temperatures of the derivative are compared with the corresponding properties of P-lactoglobulin. have reported the interesting finding that 2-methyl-lJ4-naphthoquinone has the power to inhibit the anaerobic

Over the years, therefore, the USGS has developed quite a large store of qualitative and quantitative geologic and hydrologic methods of study. In this paper, it will be possible to demonstrate only a select few of the many methods used in determining the hydrologic characteristics of ground water reservoirs.

Most of the methods proposed for determining tertiary aliphatic amines in the presence of primary and secondary amines have depended on the isolation and titration of unreacted tertiary amine after treatment 'of the mixture with nitrous acid.*s3 Mitchell, Hawkins and Smith4 determined primary and secondary amines in the presence of tertiary amines by acetylating the amines with a definite amount of acetic anhydride, hydrolyzing the excess acetic anhydride with a known amount of water, and determining the unused water with Karl Fischer reagent. Tertiary amine content of the sample could then be calculated from the total base value by difference.Blumrich and Elandel5 have proposed a simple method for the direct determination of tertiary amines, namely, the acetylation of primary and secondary amines and ammonia in the mixture by means of acetic anhydride, followed by potentiometric titration of unreacted tertiary amine by means of perch1ori.c acid in acetic acid. They reported application of the procedure to only one aliphatic amine mixture, composed of diethylamine and triethylamine.Additional data have now been obtained to determine the applicability of Blumrich's original procedure to other aliphatic amines, and the method has been found to be generally applicable except in the cases involving secondary amines with the nitrogen atom attached to secondary alkyl groups. With these sterically-hindered molecules, more drastic acetylation conditions are necessary. In testing several aliphatic amines, it was found that by acetylating under more vigorous conditions (reflux for one hour instead of allowing the mixture to stand three hours a t room temperature), such sterically-hindered secondary amines are quantitatively acetylated. It was also observed that under these conditions in the absence of acetic acid in the reaction mixture, certain tertiary amines are destroyed a t a significant rate. However, they undergo only slight, if any, deterioration when acetic acid is present in the acetic anhydride in amounts equivalent to the amines in the mixture. Water in the sample apparently does not interfere in the procedure, since the presence of as much as two grams of water does not prevent complete acetylation.(1) Present address: Reagents and Apparatus.-The standard 0.1 N acid is prepared by mixing the required amount of C . P. 70% perchloric acid with glacial acetic acid. The solution is standardized against anhydrous sodium carbonate (heat C. P. material at 400-450" for three t o four hours) dissolved in acetic acid and titrated potentiometrically or to the crystal violet end-point.A potentiometric titrometer of the direct-reading type, such as the Beckman Model M or the Precision-Shell,6 using glass and calomel electrodes, is convenient and very satisfactory for use in this analysis.General Procedure.--A sample weighing not more thaii 2 g. and containing no more than 1 g. of water is added t o 20 ml. of acetic anhydride containing 2 ml. of acetic acid. The mixture is allowed t o stand three hours a t room temperature....

The development of water supplies from wells was placed on a rational basis with Darcy's development of the law governing the movement of fluids through sands and with Dupuit's application of that law to the problem of radial flow toward a pumped well. As field experience increased, confidence in the appli cability of quantitative methods was gained and interest in developing solutions for more complex hydrologic problems was stimulated. An important mile stone was Theis' development in 1935 of a solution for the nonsteady flow of ground water, which enabled hydrologists for the first time to predict future changes in groundwater levels resulting from pumping or recharging of wells. In the quarter century since, quantitative groundwater hydrology has been enlarging so rapidly as to discourage the preparation of comprehensive textbooks. This report surveys developments in fluid mechanics that apply to ground water hydrology. It emphasizes concepts and principles, and the delineation of limits of applicability of mathematical models for analysis of flow systems in the field. It stresses the importance of the geologic variable and its role in governing the flow regimen. The report discusses the origin, occurrence, and motion of underground water in relation to the development of terminology and analytic expressions for selected flow systems. It describes the underlying assumptions necessary for mathema tical treatment of these flow systems, with particular reference to the way in which the assumptions limit the validity of the treatment. � � � 77 THEORY OF AQUIFER TESTS Unit cross-sectional area A. ARTESIAN AQUIFER Unit cross-sectional area Water table B. WATER-TABLE AQUIFER FIGURE 18 .-Diagrams for coefficient of storage. of the angle of inclination of the water table. The product of the last two factors is the component of head change acting normal to the aquifer surface. The importance of interpreting correctly the phrase "component of head change" which appears in the definition of the storage coefficient cannot be overemphasized. Examine figure 18B, which depicts, in schematic fashion, a horizontal

No abstract