Societies and Academies

Abstract

LONDON. Royal Society, November 12.—Sir William Crookes, president, in the chair.—W. L. Balls and F. S. flolton: Analyses of agricultural yield. Part I.—Spacing experiments with Egyptian cotton. The aim of the experiments is the statistical analysis of the yield of agricultural crops, in terms of plant devekpment, by careful recording of all stages. The effects of environmental conditions on crop development can then be satisfactorily analysed. The effects of varying spacing, date Of sowing, and season, upon Egyptian cotton, have been subjected in this way to critical examination by the authors. A secondary aim has been to appreciate the reasons for conventional agricultural practice. For each of twenty different spacings, the numbers of flowers daily, and of fruits, together with the weights of cotton and seed per fruit, have been recorded. The extent to which each of these components enters into the building up of the final yield is shown. The dense planting conventionally practised by the Egyptian fellah is shown to give the maximum possible yield per unit area under the limitations of field cultivation, though the normal extension of the root system of an isolated plant can utilise more than ten times the soil surface allotted to it in field crop. Most of the phenomena of field crop physiology in the fruiting season are thus shown to be traceable to root interference.—J. McIntosh and P. Fildes: The fixation of arsenic by the brain after intravenous injections of salvarsan. After intravenous injections of sal varsan and neosalvarsan in man and animals no arsenic can be found in the brain. This phenomenon is not due to lack of affinity between the brain and the drugs, but to an inability on the part of the drugs to penetrate into the substance of the brain. Fixation of arsenic by the brain occurs as readily as by the liver, as shown by experiments in vitro and the toxic effects of intrathecal injections. Penetration of neosalvarsan into the brain cannot be obtained even by frequently repeated intravenous injections.—A. E. Everest: The production of anthocyanins and anthocyanidins. Part II. The author brings forward fur ther evidence to support the conclusions arrived at by him in his previous paper (Roy. Soc. Proc., B, 1914, vol. lxxxvii., p. 144), namely, that the red, blue, and violet flower and fruit pigments (anthocyans) may be produced by reduction of flavone and flavonol derivatives in acid solution. Experiments are described which show that pure disaccharides of the flavonol series pass without hydrolysis to anthocyanins. The flavone and flavonol pigments having been previously synthesised by Kostanecki, the processes described by the author complete the synthesis of the anthocyan pigments.—H. M. Woodcock and G. Lapage: Living observations on the life cycle of a new flagellate— Helkesimastix faecicola—together with remarks on the question of syngamy in the trypanosomes. H. faecicola, ng., n.sp., occurs in goat dung and sheep dung; it is a “passenger,” being carried through the alimentary canal in an encysted state. The authors have cultivated this flagellate in various media. They have observed the entire course of the life cycle in life, from excystation to encystment.—S. W. Patterson: The antagonistic action of carbon dioxide and adrenalin on the heart. Carbon dioxide alone depresses all the functions of the isolated heart. Adrenalin, besides dilating the coronary vessels, has a specific action in increasing the rate and strength of ventricular contraction. The effect of carbon dioxide and adrenalin combined is still to allow of more rapid and stronger contraction and rapid relaxation, and also to lengthen the diastolic period. Thus, greater filling of the heart takes place, and the heart is in a better condition for putting out a maximal output.