• Volume 72, Issue 1

      July 1970,   pages  1-46

    • The florachromes: Their chemical nature and spectroscopic behaviour

      C V Raman

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      This memoir presents detailed studies of the two florachromes discovered by the author and shown by him to be responsible for the colours exhibited by a great many flowers, the two florachromes being present in the petals either separately or together as the case may be. Their characteristic absorption spectra have been photographed and reproduced and also represented as spectrophotometric records of their aqueous solutions and of the acetone extracts of the floral pigments. In appropriate circumstances, the florachromes in solution are found to be quite stable and continue to exhibit their characteristic spectroscopic behaviours permanently. The interesting discovery is recorded that Florachrome B is present as the colouring matter of the fleshy leaves of the shrubSetcreasia purpurea and can be readily obtained therefrom. The relation between the structure of the florachromes and of the well-known organic compound flavone which is itself a colourless solid is discussed and an explanation is given why there are two florachromes with distinct spectroscopic behaviours.

    • Origin and disposition of the ureter in certain Indian teleosts

      Shyama Sharma

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      The origin and disposition of the ureter inside the kidney and outside it has been investigated in the adults of five Indian teleosts—one (Notopterus notopterus) belonging to the Order Clupeiformes, and four to the Order Cypriniformes. Of the latter, two species (Clarias batachus andHeteropneustes fossilis) were siluroids, one (Trichogaster faciatus) anabantoid, and one (Caranx kalla) percoid.

    • The acetylcholine-atropine antagonism as determined by a series of pA values

      M B Gharpure

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      There is no agreement as regards the nature of the acetylcholine-atropine antagonism, that is whether it is competitive or ‘not competitive’. An attempt was made previously by the author (1964) to settle this issue by determining the pA5,000 and pA25,000 values but the results did not indicate unequivocally that the antagonism is competitive. In the present work, six pA values, namely, pA2, pA11, pA101, pA1,001, pA10,001 and pA100,001 have been determined. Two more pA values, namely, pA5,001 and pA25,001 have also been determined. The results provide an overwhelming evidence to say that the acetylcholine-atropine antagonism is competitive. Why a compound like atropine which antagonizes acetylcholine competitively even at the level of its pA10,001-pA100,001 values does not do so at the lower level of pA2-pA10 (or pA2-pA11) values still remains an unsolved problem.

      In the study of drug antagonism, such a large series of pA values and such high pA values for a pair of compounds have keen determined for the first time by the author.

    • Minerographic study of some of the sulphide ores from ingaldhal, chitaldurg district, mysore state

      A M Pathan C Naganna

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      Minerographic study of the ore samples collected from Ingaldhal copper mines shows that the ores are largely massive, banded and disseminated in structure. Pyrite, arsenopyrite, cobaltite, sphalerite, pyrrhotite, galena and chalcopyrite as primary minerals and pyrrhotite, chalcopyrite, stromyerite, bornite, chalcocite and tennantite as secondary minerals are present. The ores exhibit inclusion, panidiomorphic, mutual boundary, exsolution and replacement textures. From the mineralogical assemblage and the textures it is inferred that the ore deposits were formed inthe temperature range of 350°–500° C.

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