Abstract
IN spite of the fact that a number of papers of general interest were contributed to Section B at the Glasgow meeting, the attendance was not so good as at the Bradford meeting last year. After the reading of the presidential address, a paper was read on duty-free alcohol by Dr. W. T. Lawrence, in which it was advocated that the Government should permit the use of non-methylated alcohol which had not paid duty for scientific purposes. In the course of the ensuing discussion, Dr. T. E. Thorpe drew attention to some of the difficulties with which the Excise Department would have to cope if such a course were permitted, and Prof. A. Michael, of Boston, stated that the United States Government allowed the use of non-methylated duty-free alcohol for scientific purposes and did not seem to meet with administrative difficulties. Dr. A. G. Green presented a comprehensive statistical report on the coal-tar industry, in which the progress made in this industry in Germany during recent years was strongly contrasted with its decadence in this country. The report of the Committee on preparing a new series of wave length tables of the spectra of the elements was presented. Prof. Adrian Brown contributed a paper on enzymic action, in which he quoted the experimental results of an investigation of the action of invertase on cane sugar; these results confirm the conclusion of previous workers that the action of inversion does not follow the simple law of mass action, but the author does not regard the action as independent of mass influence. He considers that the influence of mass in inversion changes is restricted by some other and hitherto unrecognised influence, and this he believes he has found in the time factor of molecular change. In reply to remarks by Prof. Reynolds Green, the author stated that his results were not necessarily in disaccord with those of Croft Hill. A paper was read by Prof. E. A. Letts and Mr. R F. Blake, on the chemical and biological changes occurring during the treatment of sewage by the so-called bacteria beds. A large portion of the unoxidised nitrogen present in sewage disappears during the passage of the sewage through the so-called bacteria beds, and the authors consider that this may be due either to escape of the nitrogen in the gaseous state as free nitrogen or possibly as oxides or to the passage of the nitrogen into the tissues of animals or vegetables; both of these causes of loss may operate at the same time. An examination of sewage matter before and after passage through the beds showed that in nearly all cases the amount of dissolved nitrogen present in the sewage was greater after treatment than before, although, of course, if free nitrogen were evolved, only a minute fraction of it would remain dissolved in the sewage effluent. With respect to the possible biological explanation of the loss, it is pointed out that the sewage beds at Belfast and other places swaim with minute insects (Poclura aquatica), and that species of worms are also present; these in feeding on the sewage undoubtedly cause a loss of nitrogen. A paper was then read by Dr. S. Rideal on humus and the so-called irreducible residue in bacterial treatment of sewage, in which the results were detailed of a number of analyses of the humus-like substance or socalled irreducible residue produced in bacterial sewage beds. It is shown that in this material the ratio of carbon to nitrogen and the percentage of nitrogen in the organic matter present are very nearly the same as in humus mould; the con, clusion is drawn that if sewage has undergone proper bacterial fermentation the small quantity of peaty deposit formed is of the nature of humus and is practically inoffensive. In a paper on sulphuric acid as a typhoid disinfectant, Dr. S. Rideal advocated the use of sulphuric acid, either as such or in a more portable form as sodium bisuiphate, for destroying the Bacillus typhosus in potable waters or in drainage from isolation hospitals. Mr. W. Ackroyd gave a paper on the inverse ratio of chlorine to rainfall, in which it was shown that when the observation periods are shortened to daily estimations of the chlorine, minimal amounts of rainfall are marked by maximum contents of chlorine, and vice versâ. In a second paper, Mr. Ackroyd dealt with the distribution of chlorine in Yorkshire. Mr. G. T. Beilby, in a paper on the minute structure of metals, showed that the microscopic examination of metallic surfaces has revealed that metals occur in two forms, viz., as minute scales or “spicules” (a) and as a transparent glass-like substance (b). The spicules do not vary much in size in the different metals and have a diameter of 1/300 to 1/400 of a millimetre; the form a passes into the form b when the metal is pressed or hammered, and all polished metallic surfaces are covered with a thin layer of this transparent form as with a lacquer or enamel. Prof. G. G. Henderson and Mr. G. T. Beilby read a paper on the action of ammonia on metals at high temperatures; on exposing platinum, copper, gold, silver, iron, nickel and cobalt to ammonia gas at 6oo to 9OO disintegration of the metal occurs, whilst a large proportion of the ammonia is decomposed into its elements. After the treatment the metal shows a spongy or cellular structure, as if it had been rapidly cooled whilst in a state of effervescence; copper and iron rods of a quarter of an inch diameter are penetrated to the centre by the ammonia gas within half an hour, and copper exposed to the action of ammonia gas for seven days at 8oo falls to a fine powder. Dr. W. C. Anderson and Mr. G. Lean gave a paper on aluminium-tin alloys, in which they show that these alloys evolve hydrogen freely when placed in water; the microscopic examination of the water-corroded plates of alloy indicates that contact action between the excess of tin and the aluminium-tin compound is responsible forthe spontaneous oxidation. Prof. Willy Marckwald, of Berlin, gave a very interesting demonstration and description of the properties of radium; he had surmised, from the work of P. and S. Curie, that the barium salt extracted from pitchblende contains the radium salt as an isomorphous constituent, and that the process used by these workers for separating a strongly radio-active salt from the barium compound is probably similar to that in use for isolating the constituents of an isomorphous mixture. He therefore fractionally crystallised the barium chloride prepared from pitchblende fromwater, and found that pure barium chloride first separates and then a material, probably the eutectic mixture, which is very rich in the radio-active component. The most strongly radio-active fractions have the power of immediately discharging a charged gold leaf electroscope when at the distance of half a metre from the latter and whew preserved under colourless glass soon turn it a deep brown colour. The radio-active substance is strongly luminescent in a dark room, and on interposing the hand between the preparation and a barium platino-cyanide screen, the bones in the fingers are seen sharply delineated on the screen. Prof. Marckwald also exhibited several preparations of so-called “phototropic” substances, compounds which change colour on exposure to sunlight and recover their original
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Chemistry at the British Association . Nature 64, 611–612 (1901). https://doi.org/10.1038/064611a0
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DOI: https://doi.org/10.1038/064611a0