May 13, 1920] 



NATURE 



327 



the trifles which may decide events. The scientific 

 net can scarcely be cast too wide. 



... H. H. Turner. 

 University Observatory, Oxford, May 8. 



The appearance of the leading article in Nature of 

 May 6 is extremely opportune. The question is one in 

 which the scientihc world is seriously concerned, and 

 the possibility of the high cost of production stifling 

 the progress of science must lead us to consider, what 

 means can be found to obviate so disastrous a 

 calamity. It is unnecessary to quote evidence of the 

 enormous increase in the cost of printing and publica- 

 tion at the present time— that is well known — but the 

 question is accentuated by many indications that the 

 cost will go higher in the near future. 



It is very undesirable that such increased charge 

 upon the funds of scientific societies should be met 

 by raising subscriptions. No deterrent to join iocie- 

 ties should be advocated, for science is advanced more 

 by individuals than by the extent of their published 

 papers. 



The question turns upon the limitations which the 

 present state of affairs must exercise upon publica- 

 tions. It is quite certain that some curtailment is 

 necessary to avoid insolvency. It is patent to ail that 

 many papers are characterised by diffuseness and 

 redundancy, as if the value of a paper was to be 

 judged by its length. No one who wishes to keep 

 au fait with current work has time to read such — 

 conciseness and economy of expression in the treat- 

 ment of scientific papers are the desiderata. 



During the war we were rationed in our food 

 for the body, with good rather than harm to ourselves. 

 It is now necessary that the food for our minds should 

 be rationed. The only possible way to carry on until 

 things are easier is to limit publication to condensa- 

 tion or abstracts of papers, except in special cases. 

 It is not an easy task to make abstracts of papers so 

 as to retain all that is essential, and with some 

 writers it is extremely difficult to condense their 

 diffuse communications. The point might be met by 

 putting the responsibility upon authors and limiting 

 them to a definite number of pages, according to the 

 character of the paper. 



Let me give an instance where curtailment in pub- 

 lication has resulted in great economy without loss. 

 A few years ago the volume of Greenwich Observa- 

 tions extended to as many as 1400 pages. The Board 

 of Visitors decided that it was not necessary to pub- 

 lish a considerable mass of observations, as these 

 could always be supplied from the Royal Observatory 

 to anyone who wanted them, and by this means the 

 volume was at once cut down to less than 600 pages. 



E. B. Knobel. 



32 Tavistock Square, W.C.i, May 8. 



The leading article in Nature of May 6 comes home 

 to those of us who are concerned in carrying on the 

 work of scientific societies. We are making laborious 

 efforts to prune down diffuse contributions, and also 

 endeavouring to increase our income by attracting new- 

 members. Many of us regard an increase in sub- 

 scription rates as a device only to be contemplated as 

 a last resort, and are in complete agreement with 

 your article. 



The Royal Meteorological Society is directly con- 

 cerned with the question of accommodation, as well 

 as of increasing costs of publication, and we should 

 welcome any possibility of joining the privileged 

 societies that are housed by Government. Failing a 

 cash subvention for the one purpose, is it possible to 

 NO. 2637, VOL. 105] 



urge the Government to do something for us in the 

 other direction? I should like to press for the 

 removal of the Civil Service Commission from Bur- 

 lington Gardens. Examir^ations might well be held 

 in university rooms at South Kensington or else- 

 where. I do not know how many societies could find 

 adequate room in the building if it were thus set 

 free; but it seems to me that assistance of this kind 

 would be, at any rate for those of us who secured it, 

 better than a subvention towards printing expenses, 

 and possibly easier to obtain from the Government. 

 Walter W. Bryant, 

 Hon. Sec, Royal Meteorological Society. 

 Royal Observatory, Greenwich, S.E., May 8. 



Atomic and Molecular Forces and Crystal Structure. 



One of the most difficult problems in the theory of 

 chemical valency is to form a clear picture of the 

 attractive forces between similar atoms. Lewis and 

 Langmuir, in their theory of the cubical atom, have 

 each attributed the single valency bond to the mutual 

 action between a pair of electrons, and Langmuir has 

 recently pointed out (Nature, April 29, p. 261) that, as 

 regards chemical considerations, such a pair of elec- 

 trons may be regarded as revolving in the same orbit. 

 This idea is closely allied to Bohr's construction for 

 the hydrogen molecule. It should, however, be 

 pointed out that such a construction leads to a strong 

 paramagnetic property for molecular hydrogen, unless 

 the electron motions are compensated by rotation of 

 the nuclear charges. Such compensation is scarcely 

 likely, since the magnetic moment depends on the 

 area of the orbit described, and evidence up to date 

 points to a nuclear radius of small order compared 

 with that of the electron orbit, even though the latter 

 be small compared with the conventional radius of 

 the atom. 



X Y 



-f^ 



Model of hydrogen molecule. 



Suppose X and Y are two exactly similar hydrogen 

 atoms. Their nuclei are shown at A and B, and the 

 negative electron orbits at a and b. The nucleus A 

 may control the orbit a electrostatically and mag- 

 netically, while B controls h. As shown, there will 

 be magnetic attraction between a and h, and possibly 

 also a certain amount of electrostatic repulsion if each 

 electron is not completely bound to its own nucleus. 

 Equilibrium may be established for some such dis- 

 position of the charges as that indicated. We thus 

 get a sort of fusion of the two hydrogen atoms which 

 corresponds to the fusion of the electron orbits in 

 Bohr's theory of the hydrogen molecule. In the 

 present case, however, the fusion is controlled mag- 

 netically, whereas in Bohr's theory it is purely electro- 

 static. 



The system depicted above gives a diamagnetic 

 hydrogen molecule as required. 



With more complicated systems, we can see, in a 

 general way, how the small circular orbits will dis- 

 pose themselves in pairs (Lewis and Langmuir) 

 primarily under their mutual magnetic influences. 



