The necessity of carrying out additional preparatory work on the foundation of the hydroelectric plant and the abutments was dictated by the complex geologic structure and the nonuniform, often low, density of the sands of the Shevchensk formation under those structures.* The mass of pure quartz sands (river bed and scour facies), which have different grain sizes and stratification characteristics, contains seams and lenses of clay soils belonging to an ancient facies, clay pockets, organic residual soils, and seams of clay sands, noted for their low bearing capacity. The weak soil seams have an extremely nonuniform development, vertically and in plan (Fig. 1). On the right bank abutment, in the upper wing, additional excavation of moraine deposits was carried out.

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The question of further improvements in the methods used in engineering-geologic investigations is a very real problem, and has not only an important theoretical significance, because it is directed at achieving a practical object, viz., to raise the efficiency and quality of this work, which is one of the main problems of the 10th Five-Year Plan.New methodological principles, which touch upon the whole "investlgations--design-construction" system, are characterized by a sharply defined structure which provides for the following components: a) a differentiated approach in determining the volume of work, depending on the importance (degree of responsibility) of the structures; a purposeful trend in investigations of studies of the main engineering-geologic factors in connection with items of the first category of responsibility (main structures); b) a wide utilization (particularly in the initial design phases) of the less expensive, indirect and rapid methods, and also of natural analogues and experience, in investigations, design, and construction; c) the verification and final solution of a series of controversial questions during the construction period, which will raise the role of engineering-geologic documentation of construction excavations and cuts.In the writer's opinion, a wide introduction of new methodological principles into investlgational practice should be preceded by the development of a single approach to their use in all subdivisions of work in engineering-geologic investigations.A very important point in the course of Investigatlonal work is an assessment of the significance of one or another engineerlng-geologlc factor for design or construction. Investlgational experience shows that in several cases, errors by geologists occurred precisely because the main, determining factors were relegated by them to the secondary category; this occurred, e.g., in the evaluation of the role of thin clay seams in a formation of seml-rock and rock materials of the Proterozoic, on the stability of slopes in the region of the Dnester hydroelectric scheme. It is well known that such difficulties often arise when assessing the role of tectonic joints or other weakened surfaces on the stability of high slopes in a formation of brittle but jointed rocks, especially in poorly exposed zones where an engineering-geologic survey and simplified methods are obviously insufficient for a solution of the problem.Experience has shown that in some cases the classification of englneering-geologic features into primary and secondary categories is not a simple problem, whose solution demands a considerable volume of work because the importance of concrete natural factors for design is not determined a priori but is classified in the course of investigations.

Research in the field of adrenal cortical function has been limited by the inability of existing techniques to measure precisely the kind and amounts of steroids elaborated by the gland. Particularly in man, the indicators have been indirect and inadequate. These have consisted principally of the alterations in certain non-steroid constituents of the blood, changes in the total number of circulating lymphocytes and eosinophils, and variations in end products of steroid metabolism found in the urine. Biological assays (1, 2) of the blood level of adrenal cortical hormones were developed with the hope that they would provide greater specific-ity, but have proved to be neither sufficiently sensitive nor precise. Chemical methods (3, 4, 5) for the determination of blood steroids have been proposed. The first satisfactory direct quantitative measurement of 17-hydroxycorticosteroids in the blood of human subjects was reported by Nelson and Samuels (6).

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