November 4, 19 15] 



NATURE 



275 



tion of the velocity is produced in some cases by 

 chlorides and hydroxyl ions. Small concentrations of 

 sulphates produced an acceleration. Prof. Francis 

 pi tinted out that the order in which the salts effected 

 rh ' velocity constant was that found in the lyotropic 

 ii s, iodides producing the greatest and chlorides the 

 I effect. 



>i". N. V. Sidgwick pointed out that while Prof. 

 vis assumed the catalytic activity to be propor- 

 late to the amount of catalyst, this was not always 

 luif, and further that temperature coefficients of iso- 

 meric changes and mono-molecular changes in general 

 are abnormally high. The immediate need before pro- 

 ling to theory is an accumulation of more exact 

 rimental data. 



Trof. E. C. C. Baly from spectroscopic observations 

 considered that as the first step in a chemical change 

 must be the conversion of the reacting substance into 

 an intermediate verj' reactive state, a positive catalyst 

 must be an agent which converts more substance into 

 this state. This intermediate state results from the 

 introduction of a definite amount of energy. He sug- 

 gested that probably the actual amount of energy thus 

 needed was constant and independent of the value of 

 the vibration frequency, and that the numbers of 

 energy quanta necessary to produce the critical incre- 

 ment at any given vibration frequency of the molecule 

 are numerically related to one another. Further, the 

 relation between the active and inactive forms does 

 not obey the law of mass action. 



It may be fairly concluded from the discussion that 

 far more experimental data must be accumulated, par- 

 ticularly as regards temperature coefficients and 

 changes of velocity with increasing amount of catalyst. 



Other parts of the mornings were occupied with 

 several short papers, of which space will only permit the 

 titles. Dr. H. F. Coward and Prof. A. Harden de- 

 scribed and exhibited some lecture diagrams used 

 by Dalton in illustration of his atomic theory ; Dr. A. 

 Hynd, "Configuration in the Sugar Group"; Dr. 

 H. J. S. Sand, "A New Cadmium Vapour Arc Lamp" ; 

 Dr. Robert Mond, " Ruthenium Di-Carbonyl " ; Dr. 

 W. E. S. Turner, " lonisation in Solvents of Low 

 Dielectric Constant," and, jointly with Mr. J. D. 

 Cauwood, "The Molecular State of Salts in Solution." 



On one afternoon Prof. W. J. Pope gave an experi- 

 mental lecture on liquid crvstals, and on the other 

 Prof. W. A. Bone, Prof. H. B. Dixon, and Dr. H. F. 

 Coward contributed papers on combustion and explo- 

 sion of gases with some experimental illustrations. 



The account of the work of the section would not 

 be complete without a word about the discussion on 

 isotopes, which took place in Section A, but which 

 was peculiarly interesting to chemists. The discus- 

 sion is summarised in the report of the proceedings of 

 Section A in Nature, but results obtained by Dr. 

 Whytlaw Gray from microchemical experiments 

 showed that certain salts, iodides, chlorides, chromates, 

 etc., of the product of decay of radium emanation 

 are identical as far as solubility, crystalline form, etc., 

 with the corresponding salts of lead. Approximate 

 determinations of their melting points also indicated 

 identity. To the chemist this is perhaps more con- 

 vincing than a volume of deductions by a physicist. 



GEOGRAPHY AT THE BRITISH 

 ASSOCIATION. 



THE president of the section, Major Lyons, was 

 unable to be present, owing to pressure of work 

 in connection with the war, and his address, the main 

 part of which was printed in Nature of September 23, 

 was read by Mr. H. Yule Oldham. His other duties 

 were undertaken by the vice-presidents, Mr. G. G. 



NO. 2401, VOL. 96I 



Chisholm, Prof. J. W. Gregory, Mr. Harry Nuttall, 

 and Mr. H. Yule Oldham. 



On Wednesday morning Mr. A. R. Hinks gave an 

 account of the map which is being compiled at the 

 Royal Geographical Society under the direction of the 

 General Staff on the scale of i ■ 1,000,000. After a 

 brief statement regarding the inception and progress 

 of thfe map, and the principles upon which it is being 

 compiled, he referred in more detail to various 

 methods of showing relief, the selection of names, the 

 index to boundaries, and marginal names. Mr. B. C. 

 Wallis followed with a paper on methods of represent- 

 ing the distribution of population upon maps, and 

 more especially upon the maps already described by 

 Mr. Hinks. Taking the Buda-Pest sheet, he showed 

 how the population in each administrative area might 

 be assumed to be evenly distributed throughout, and 

 how the density when located in the centre of the 

 area might be treated in the same way as a spot 

 height in contouring. He also showed maps, and dis- 

 cussed methods for the representation of the various 

 ethnic elements in the population. 



Wednesday afternoon was devoted to a series of 

 short papers by members of the section who had been 

 present at the Australian meeting. Mr. O. J. R. 

 Howarth compared several well-known maps show- 

 ing the distribution of vegetation in Australia, and 

 pointed out the great discrepancies which existed 

 between them. He suggested that a committee might 

 at some suitable time be appointed to examine and 

 criticise the material upon which distributional maps 

 in general are based, and that such a committee might 

 begin its labours by a consideration of the material 

 available for the construction of vegetation maps of 

 Australia. 



Prof. J. W. Gregory discUssed the relations of the 

 central lakes of Westralia, which he believes to be 

 basins left by the dismemberment of a Miocene river 

 system. He considers that the drainage from lakes 

 Giles, Barlee, and Ballard originally passed through 

 Lake Raeside south-eastward to the sea, and that the 

 channel from Lake Ballard south-west through Lake 

 Deborah to the Swan River, indicated on a recent 

 contour map of Western .Australia, was of later date 

 and was formed by the blocking of the south-eastern 

 outlet by wind-borne drifts. 



Mr. j. McFarlane described the Burrinjuck Dam 

 and the Murrumbidgee irrigation area in New South 

 Wales, with special reference to the interaction 

 between man and his environment in an irrigation 

 area. 



Mr. H. Yule Oldham explained the various stages 

 in the explorations by which the outline of the 

 Australian continent had been filled up. 



Thursday morning was devoted to joint discussions 

 with Sections C and H respectively. The discussion 

 with Section C on the classification of land forms 

 was opened by Dr. J. D. Falconer, who proposed to 

 set up two classes of land forms, each containing two 

 orders : — 



class A. endogenetic forms : Order L, negative 

 forms; Order H., positive forms. Class B, 

 exogenetic forms: Order L, degradation forms; 

 Order H., aggradation forms. 



The two orders of endogenetic forms are then sub- 

 divided into four families : — 



Family i. Forms due to superficial volcanic activity. 



2. Forms due to sub-crustal volcanic activity. 



T,. Forms due to radial movements. 



4. Forms due to tangential movements. 



Similarly, the two orders of exogenetic forms are 

 each subdivided into nine families : — 



Family i. Forms due to the action of the run-off 



2. Forms due to the action of percolating water. 



