Abstract
LONDON. Royal Society, November 13.—Sir J. J. Thomson, president, in the chair.—Lt.-Col. R. McCarrison: The genesis of œdema in beri-beri. Conclusions previously reached by physiological methods of adrenalin estimation are confirmed by chemical methods. Deficiency of certain accessory food factors gives rise to a greatly increased production of adrenalin. Whatever the function of adrenal medulla may be, excessive production of adrenalin, under conditions of “vitaminic” deficiency, is concerned with causation of œdema.— W. Robinson: The microscopical features of mechanical strains in timber and the bearing of these on the structure of the cell-wall in plants. The gross and microscopic characteristics of failure in compression are described for spruce, ash, and pitch pine. It is shown that failure is initiated by the development of microscopic planes of slipping in the cell-walls of the wood. The appearance of the slip planes in the cell-walls is accompanied by profound changes in the behaviour of the latter towards many stains and reagents. These changes are discussed in relation to their possible bearing on the process of lignification of cell-walls. In addition to compression, the failures in longitudinal tension and longitudinal shearing are described.—W. B. Bottomley: The effect of nitrogen-fixing organisms and nucleic acid derivatives on plant-growth. The products of the nitrogen-fixing organism, Azotobacter chroococcum, are shown to have a marked effect in increasing the rate of growth of plants of Lemna minor in water culture; and the derivatives of nucleic acid, which the author has found can be extracted from raw peat, are also able to act as accessory food substances. The addition of these two separate materials to the culture solution increased the number of plants from 1817 in mineral solutions only to 96,921 and 80,179 respectivelv in the liquids containing these substances. Not only was the rate of multiplication increased bv these organic materials, but the plants supplied with them also maintained their normal size and health. The nitrogen-fixing organism. Bacillus radicicola, is found to have a similar effect to that of Azotobacter chroococcum. A similar series of experiments was carried out with the ash of the crude nucleic acid derivatives and of the Azotobacter growth, and neither of these materials had the slightest effect on the rate of multiplication or the health of the Lemna plants. It is therefore the organic material which is so essential for the complete metabolism of these plants, and they cannot maintain their normal growth and vigour for any length of time without the presence of small quantities of organic substances.—Agnes Arber: The vegetative morphology of Pistia and the Lemnaceae. Anatomical examination of the “limb” of the leaf of Pistia stratiotes, L., the river lettuce, shows that, in addition to normally orientated vascular bundles, there is a series of inverted bundles towards the upper surface. This fact is regarded as indicating that the leaf is of the nature of a petiolar phyllode. This interpretation is extended to the distal part of the frond of the Lemnacese (duckweeds).—W. J. Young, A. BreinI, J. J. Harris,and W. A. Osborne: Effects of exercise and humid heat upon the pulse rate, blood pressure, body temperature, and blood concentration. The results point to the fact that both exercise and humid heat play a part in producing a rise in blood pressure, pulse rate, . and rectal temperature. The degree of rise, however, is controlled by atmospheric conditions, which influence the rate of cooling of the body.
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Societies and Academies . Nature 104, 345–347 (1919). https://doi.org/10.1038/104345a0
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DOI: https://doi.org/10.1038/104345a0