September 9, 1897] 



NATURE 



463 



values Xi=58-69, and €0 = 5899 will take their places as 

 standards among the numerous other results, which have been 

 obtained in such rapid succession in the laboratory of Harvard. 



One of the most attractive items on the programme of the 

 section was the demonstration of the preparation and properties 

 of fluorine, by Prof. E. Meslans. Since the Nottingham meeting, 

 at which the demonstration was made for the first time in 

 England, an important simplification has been introduced into 

 the apparatus required for the production of the gas, which will 

 probably render it possible to include the preparation of this 

 element in the ordinary course of lecture experiments, and may 

 even lead to its economical production on the large scale, should 

 any industrial application of the gas be found desirable. The 

 latest form of apparatus consists entirely of copper, and is 

 larger than the costly platinum apparatus of Moissan, although 

 the same general shape is preserved. The a|l)paratus is charged 

 in the usual way, and is then itself connected with the positive 

 terminal of a battery, the two eleectrodes being made the nega- 

 tive pole. Fluorine is thus evolved at the internal surface of 

 the apparatus, and a thin non-conducting layer of copper fluoride 

 is deposited upon it. The apparatus after this preliminary 

 treatment is employed exactly in the same way as Moissan's 

 platinum apparatus, but may be simply cooled by ice and salt. 

 The presence of the non-conducting layer of copper fluoride 

 prevents the passage of electricity from the electrode to the side 

 of the vessel, and thus avoids the consequent loss of fluorine ; so 

 that the yield in the new modification of the apparatus is much 

 greater than in the original form. 



Several papers on subjects connected with physical chemistry 

 were contributed. The first of these was read by Prof. H. B. 

 Dixon, in continuation of his previous work on explosions of 

 gases, and dealt with the curious phenomena attending the 

 commencement of an explosion in a gaseous medium, which 

 may be investigated by photographing the flash. If the mixture 

 be fired at the end of a tube, the disturbance very gradually 

 increases in velocity as it passes along the tube, until after a 

 comparatively great distance has been traversed, the velocity 

 characteristic of the mixture is reached. When, how- 

 ever, the firing-point is 3 or 4 inches from the end of the 

 tube, the disturbance passing slowly down the longer portion of 

 the lube is reinforced by the wave which has traversed the short 

 distance to the end of the tube, and has there been reflected. 

 After this reinforcement, the united disturbances travel at a much 

 more rapid rate, and the maximum velocity is quickly attained. 

 Another investigation on the mechanism of a reaction, but from 

 a difl'erent point of view, was described by Dr. J. W. Walker in a 

 paper dealing with the reaction between hydrobromic and bromic 

 acids in aqueous solutions. Time measurements of the rate ot 

 liberation of bromine show that most probably the reaction 

 does not take place between six molecules as indicated in the 

 ordinary equation, but between two. It is therefore probable 

 that the reduction of the bromic acid takes place in stages, 

 bromous and hypobromous acids being probably formed as 

 intermediate products. Dr. W. L. Miller, of Toronto Univer- 

 sity, in a paper on the vapour tensions of mixed liquids, ex- 

 plained the method adopted by himself and Mr. Rosebrough for 

 testing the validity of Gibb's equation for the equilibrium of the 

 vapours of mixtures of liquids at constant temperatures, and 

 demonstrated that actual determinations of the composition of 

 the vapour given off from various mixtures of alcohol and water 

 agree very closely with the calculated numbers. The Rontgen 

 rays again formed the subject of an investigation at the hands 

 of Dr. J. II. Gladstone and Mr. W. Hibbert, who have com- 

 pared the absorptive power of various salts of the same metal 

 (lithium), and have thus obtained relative values for the various 

 acid radicals. 



A number of short papers on organic chemistry were com- 

 municated to the section, including a review by Prof. P. C. 

 liter, of his work on the constitution of acetone and other 

 analogous ketones ; the formation of a benzene ring by the 

 reduction of a i-6-di-ketone, by Dr. A. Lehmann ; condensation 

 products of aldehydes and amides, by Dr. C. A. Kohn ; and on 

 the nitro-alcohols, by Prof. L. Hemy, of Louvain. Great 

 interest was excited by a very able paper on the chemistry ot 

 methylene, by Prof. J. V. Nef, of Chicago, in which the latest 

 results obtained in the study of compounds containing dyad- 

 carl)on were described. Prof. Nef has obtained a very unstable 

 series of substances which he regards as acetylidene derivatives, 

 CR._. = C, isomeric with the normal acetylene derivatives 

 RC'E CR. The di-iodo-compound is the most stable, 



NO. 1454, VOL. 56] 



but even this slowly burns when exposed to the air, 

 whilst the other derivatives undergo a much more rapid 

 combustion under the same circumstances. All the com- 

 pounds are violently poisonous. The di-iodo-derivative can be 

 prepared in a number of different ways, the most interesting 

 of which are (i) the direct action of sunlight on tetra-iodo- 

 ethylene, I„C = CIj, one molecule of iodine l>eing liberated ; 

 and (2) the action of iodine on silver acetylene. On oxidation 

 it appears to primarily yield carbonic oxide and iodine, but the 

 latter converts a portion of the unaltered compound into tetra- 

 iodo-ethylene. The monobromo-derivative bears in its proper- 

 ties a most remarkable resemblance to phosphorus, and is termed 

 by its discoverer " vegetable phosphorus, " since it shines in the 

 dark, burns on exposure to the air, and acts as a violent poison, 

 in the same way as phosphorus. 



Several papers dealing with local problems were presented by 

 various chemists. The most elaborate of these was a very ex- 

 tensive series of analyses of the virgin soils of Canada, sub- 

 mitted by Dr. F. T. Shutt, who occupies the important position 

 of chemist to the Dominion Experimental Farm at Ottawa. 

 These showed that some of the prairie soils of Manitoba are of 

 extraordinary richness and fertility, whilst the soils of Canada 

 in general may be considered as of a satisfactory character for 

 agricultural purposes. Some interesting analyses of coal from 

 the pre-carboniferous rocks of Canada were communicated by 

 Prof. Ellis, of Toronto. These showed in a very striking way 

 j the gradual transition from petroleum and its immediate pro- 

 I duct of decomposition, asphalt, to anthracite and pure carbon. 

 I Prof. Roberts-Austen showed a number of interesting slides, 

 j which supplemented the information given in his evening lecture 

 I on the metals of Canada, as to the close similarity of the pheno- 

 i mena exhibited by ordinary liquids, and metals in the molten, 

 I and even in the solid form. Mr. Ramage also exhibited a series 

 ! of slides, reproduced from photographs of the spectra of various 

 ! metals and minerals in the oxyhydrogen flame, showing the 

 j presence of many unsuspected constituents in very small 



amounts. 



j Great interest was shown in a demonstration by Prof. Andrews, 



I of the plaster of Paris method in blowpipe work. In this 



I method charcoal is replaced by a thin, oblong tablet made of 



plaster of Paris, mixed with a little boric acid. This can be 



employed for all the ordinary tests which are conducted on 



charcoal or platinum wire. Prof. Andrews has, moreover, 



I ekborated a series of extremely delicate and characteristic tests 



j for a large number of metals, which depend on the coloured 



films produced when compounds of these metals are treated 



j with a solution of iodine in potassium thiocyanate. These 



! consist partly of oxide and sulphide, partly of iodide and 



oxyiodide, and are very brilliant in colour. Although not so 



suitable for teaching purposes, these iodide films afford a very 



ready method for the detection of the constituents of a metal in 



the field, and will no doubt be welcomed by practical 



mineralogists. 



An interesting, though somewhat speculative, attempt was 

 made by Mr. L. T. Addison to refer the diflerent crystalline 

 forms and specific gravities of the allotropic forms of many of 

 the elements to different modes of arrangement of the same 

 primal forms, the shape of which is intimately connected with 

 the valency of the element. 



A break in the routine of business was enjoyed by the mem- 

 bers of the section on Saturday, when a visit was paid to the 

 electric power-house at Niagara, and the works for the pro- 

 duction of carborundum and of soda by the electrolytic process, 

 which are in its immediate neighbourhood, and derive their 

 energy from the diverted waters of the Fall. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 

 Dr. Julius Hann, Director of the Vienna College of 

 Meteorology, has been appointed professor of meteorology at 

 Gratz, in Styria. Prof. Joseph Pernter, professor of cosmical 

 physics in Innsbruck University, has been appointed to the 

 vacancy caused by Dr. Hann's retirement from the Vienna 

 College. Dr. E. von Esmarch, assistant professor of hygiene 

 at Konigsberg, has been made full professor. Mr. William 

 Saunders, second master at the Cardigan Intermediate School, 

 has been appointed head master of the Radnorshire County 

 School at Llandrindod Wells. 



