This paper provides the verification of coefficients for the calculation of particle density, bulk density, and total porosity based on the texture of soils proposed by Brogowski (1990). The verified and supplemented coefficients for the calculation of particle density, bulk density, and total porosity permit obtaining credible results within the range of analytical errors. The proposed calculations of density and total porosity of soils can be used for the general description of soils. They cannot, however, replace exact scientific research on the physical state of soils.

The aim of this research was to finding methods of calculating the content of water unavailable to plants in the total soil mass based on the water properties of particular grain sizes. Fractions <0.02 mm bind from 90.1 to 98.8% of total water unavailable to plants in soils, and the clay fraction (<0.002 mm) alone binds from 52.1 to 80.1% of this water. Binding water in fractions <0.02 mm significantly depends on the mineralogical composition of fractions. The presence of illite, chlorite or kaolinite causes a decrease of capacity of water unavailable to plants by even 40% in relation to fractions composed of smectites, vermiculites, and humus. Due to high variability of the capacity of water unavailable to plants in particular grain size fractions <0.02 mm resulting from the variable mineralogical composition of this fraction, coefficients allowing to calculate the capacity of water unavailable to plants in soil microcapillaries below 0.2 µm show very high oscillation and could not be applicable.

The distribution of organic matter in the genetic horizons of lateritic soil within a 100-cm profile to the basaltic parent rock is almost except for horizon Ap. Assuming that the sum of organic matter in 100 cm of the soil profile is 100%, 25.7% of these compounds occur in horizon Ap, whereas in the remaining horizons this value varies within 18-19.2%. In all size fractions, except the clay fraction in diameter of <0.002 mm, the content of organic matter decreases to a certain depth, and increases again in the deepest horizon located directly on the solid basaltic rock. The clay fraction displays an opposite trend; the content of organic matter in them increases with depth. In the horizon at the depth of 60-80 cm, the clay fraction <0.002 mm accumulates half of the total sum of organic compounds of all the remaining fractions. Such distribution of organic matter in soil and among its particle size probably results from the character of the basaltic weathered debris, as well as climate and vegetation covering the studied area.

Racemform von V aus; Einengen der Mutterlauge ließ noch weiteres inaktives V ausfallen; aus der Mutterlauge fiel nach starkem Einengen und auf Zugabe von Petroläther stark aktiviertes Material aus. Von ca. 50proz. Aktivierung an lieferte erneutes Umkristallisieren aus Benzol audi ein optisch aktives Erstkristallisat: es wurde in weitere Fraktionierungen eingesetzt. Das in Benzol sehr viel besser lösliche Mutterlaugen-Kristallisat wurde nunmehr aus Petroläther (Siedebereich 60 bis 70°) analog konsequent weiter fraktioniert.Kieselgel-Chromatographie in Benzol und rasches Sublimieren (höchstens 0,1 g-Portionen!) bei 90° und 0,001 Torr gestattete die Abtrennung von den in den leichtest löslichen Fraktionen angereicherten Fremdbeimengungen, ohne daß Racemisation bemerkbar war. Anschließendes viermaliges Umkristallisieren, zuletzt aus Alkohol, erbrachte keine Änderung der Schmelzpunkts-und Drehwerte mehr. Aus insgesamt 70 g eingesetztem (±) V wurden so direkt je 600 mg der beiden V-Enantiomeren mit Höchstdrehung, ferner noch je rund lg ( + )-bzw. (-)-Material mit [a] 405-Wer-

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