February 2, 1922] 



NATURE 



153 



Chemistry at the British Association. 



THE attendance at Section B during the Edin- 

 burgh meeting of the British Association was 

 exceptionally large, and was well maintained 

 throughout, so that, although the meeting-place of 

 the section was the commodious chemistry lecture- 

 room of the University, it was sometimes impossible 

 to find accommodation for all those who wished to 

 hear the discussions. The joint meetings with other 

 sections were very popular, and the practice adopted 

 by the section in recent years of having only a 

 small number of papers at each session led to the 

 interest in the proceedings being well maintained 

 owing to the full discussion of important papers. 



The programme contained a number of contribu- 

 tions to the subject of chemistry in its bearing on the 

 problems of animal and vegetable life. The joint 

 discussion with the Section of Physiology on oxida- 

 tions in living tissues has already been reported 

 (Nature, November lo, 192 1, p. 353). The president's 

 address on "The Laboratory of the Living Organism " 

 (Nature, October 20, 192 1, p. 243) was one of the 

 most successful features of the meeting. Dr. Forster 

 omitted the more technical portions of his printed 

 address, and delivered an exceptionally lucid lecture 

 which must have made clear to many students 

 of chemistry who had not previously studied 

 recent work in biochemistry both the import- 

 ance of the subject and the fascinating character 

 of the reactions which take place at atmospheric 

 temperatures and without the presence of ener- 

 getic condensing agents in the living organism. 

 The paper by Prof. Robinson, which followed on the 

 presidential address, elaborated one aspect of the 

 same subject, the author indicating the reactions by 

 means of which flavones, anthocyans, and other com- 

 pounds which occur naturally as plant pigments may 

 be derived from carbohydrates by condensations which 

 are capable of occurring at the atmospheric tem- 

 perature. 



Profs. Baly and Heilbron and Mr. Barker dealt with 

 the synthesis of formaldehyde and carbohydrates from 

 carbon dioxide and water under the influence of light. 

 These reactions are brought about by light of very 

 short wave-length, but in the presence of certain 

 coloured substances, which act as photo-catalysts, 

 they can take place in light of a lower frequency. 

 Chlorophyll, on account of its optical properties, is 

 an ide^l photo-catalyst for both stages of the carbo- 

 hydrate synthesis. Dr. E. J. Russell pointed out that 

 although magnesium is an essential constituent of 

 y chlorophyll, the addition of magnesium salts to the 

 soil does not increase the amount of photo-synthesis 

 in plants, as does the addition of that of potassium 

 salts. He also remarked that the first product of carbo- 

 hydrate synthesis in the plant is cane-sugar, which is 

 then hydrolysed. The formaldehyde hypothesis, pro- 

 posed fifty years ago by von Baeyer, is thus still a 

 matter of controversy. A paper by Prof. Jaeger, of 

 Groningen, had to be taken as read on account of 

 the time occupied by the preceding discussions. In 

 this the author showed that the decomposition of 

 simple organic acids and their salts in solution bv 

 ultra-violet light was in a high degree dependent on 

 the presence of catalysts, the results thus having a 



iring on the question of photo-synthesis. 



\nother group of papers dealt with physical 

 v.aniistry. The discussion on the structure of mole- 

 cules, held jointly with Section A, was highly suc- 

 cessful, and has already been reported (Nature, 

 October 13, 1921, p. 218). Theories of atomic 

 NO. 2727, VOL. 109] 



structure, which have hitherto been the special con- 

 cern of the physicist, are now invoked to explain 

 chemical phenomena, especially those connected with 

 valency ; hence the new interest taken by chemists in 

 the subject. Three papers on surface tension were 

 also communicated to the section. Prof. Jaeger 

 described the experimental methods by which he has 

 been able to measure the surface tension of liquids 

 between the temperatures of -80° and +1625° C. The 

 method consists in determining the pressure needed 

 to cause a gas bubble to burst when emerging from a 

 platinum capillary immersed to a known depth in 

 the liquid. The results obtained from molten salts 

 indicate that if Eotvos's relations be assumed to hold, 

 these liquids must be highly associated, but that the 

 validity of the assumption is doubtful. The method 

 is not applicable to metals, as it is necessary that 

 the liquid should wet the platinum. Mr. Cosmo 

 Johns described his observations on the surface of 

 freely flowing liquid steel. The optical properties 

 of such a surface indicate that it is free from oxide, 

 and the author has previously explained this fact as 

 being due to an atmosphere of iron vapour. Evidence 

 for such an atmosphere was now given, the particles 

 collected from the atmosphere near to the' outlet of 

 the furnace .being relatively richer in manganese 

 (the more volatile metal). The behaviour of these 

 fine particles under the influence of gravity and of a 

 magnetic field was also described. Prof. Desch gave 

 an account of measurements of foam cells in soap 

 and other foams. The most frequently occurring 

 figure proved to be the pentagonal dodecahedron, 

 slightly distorted. An examination of the crystal 

 grains of several metals proved that these grains 

 had the form of foam cells, graphs showing the 

 frequency of occurrence of similar faces coinciding 

 completely, from which the conclusion was drawn 

 that the grain boundaries are determined by surface 

 tension. 



A question of national interest was raised by the 

 paper on the modern dye industry contributed by 

 Prof. H. E. Fierz, of Zurich. The main argument 

 of the paper was that the capacitv for production of 

 dyes now largely exceeded the demand, and that it 

 was impossible for the dye industry to remain self- 

 contained. The intermediate and final products lent 

 themselves readily to conversion into pharmaceutical 

 and photographic chemicals, technical colloids (vis- 

 cose, bakelite, etc.), and similar products. The 

 chemical industry must therefore be regarded as a 

 whole, and a new organisation was necessary. 



A discussion on atmospheric pollution by smoke 

 concluded the session. Dr. Owens described the 

 apparatus used by the Advisorv Committee, and 

 showed records taken at various stations in London, 

 whilst Mr. W. Thomson described the somewhat 

 different apparatus used in Manchester, and exhibited 

 a long series of records from that town. The prin- 

 cipal difference noticed was the regular occurrence of 

 a weekly maximum on Monday in the smoke pollu- 

 tion of Manchester, which was never observed in 

 London. That the clearness of the atmosphere during 

 the coal dispute of 192 1 was due to the absence of 

 smoke, and not merely to the exceptionally fine 

 weather, was proved by comparing the sunshine 

 records from different parts of the same town. The 

 report of the Fuel Economy Committee, which had a 

 bearing on the same subject, was received, but was 

 not discussed by the section. 



The sittings ' for the reading and discussion of 



