898 



NATURE 



[UttEMBtK 22, 1923 



Letters to the Editor. 



[ Tkt Editor does not hold hints f If rf sponsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return^ nor to correspond with 

 the writers of rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications^^ 



Hydrone and Water : Thunderstorms and 

 Globe Llithtnlnit. 



Prok. Armstrong (Nature, Dec. 8. p. 827) 

 humorously appeals to me and other physicists to 

 rush in and immerse ourselves in his aqueous diffi- 

 culties, where apparently he hesitates to tread. Had 

 FitzGeralcl been alive he might have been a willing 

 victim, for he was always ready to apprehend the 

 difficulties of others and often illuminated them by a 

 flash of genius. 



I^of. Annstrong sometimes seems more at home in 

 an atmosphere likely to generate heat, than in the 

 placid evolution of electricity or light ; but in this 

 instance he really does seem to want a question 

 answered, though he does not put it very clearly. If 

 he wishes us to enter a complex molecular assemblage, 

 like hydrone, we may soon get out of our depth ; ifor 

 we know that he despises HjO, and even H2O is not 

 as clearly apprehensible as we should like, in terms of 

 atomic structure. A molecule as big as a fist would 

 in some respects be advantageous. But what has 

 that to do with electrical manifestations ? 



If we reply to Prof. Armstrong's apparent question 

 in terms of elementary electricity, we shall be told — 

 no doubt with perfect truth — that chemists knew all 

 that before. Still, I will run the risk of a few plati- 

 tudes. Dr. G. C. Simpson and I have both answered, 

 publicl)' or privately, about the effect of aggregating 

 small charged spheres into large ones, or vice versa ; 

 so to this I will only add that I am more disposed 

 than is Dr. Simpson to attribute a great deal of atmo- 

 spheric electricity to the influence of an outside source, 

 namely, the sun. But Prof. Armstrong says that his 

 point is more fundamental than that. He harps upon 

 the need for electrodes, and constantly uses the term 

 " circuit." I suggest that he rather over-emphasises 

 these things. Electrodes are only necessary if the 

 separated charges are to be conveyed to a distance 

 by conduction : but they can travel by convection, 

 and electrical separation can occur by displacement. 

 Electrodes are needed for a galvanometer, not for a 

 gold-leaf electroscope. 



Examples. — A crystal of tourmaline warmed or 

 cooled will exhibit opposite electrifications at its two 

 ends, and if the crystal could be broken they would 

 be separated. Pressure applied to other crystals 

 shows a similar effect. Any conductor properly 

 broken in an electric field will separate the electricities, 

 just as silk rubbed on glass will exhibit electric 

 separation when pulled apart. The same sort of 

 thing Dr. Simpson expects in broken water drops. 

 And certainly Armstrongs (both of the name) well 

 know that drops of pure water propelled through a 

 suitable nozzle will emerge electrified. In none of 

 these cases are there electrodes, or any obvious 

 circuit, and yet electric energy is displayed! 



In a sense, it is true, there must always be a 

 circuit of some kind. Electricity behaves rather Uke 

 an incompressible fluid of which space is completely 

 full. We cannot generate electricity ; we can only 

 separate or decompose and move apart the opposite 

 kinds. But the circuit may be completed by in- 

 sulated displacement, as well as by conduction. 



The position is a little complicated by the singular 

 and surprising fact that positive^electricity is more 



NO. 2825, VOL. I 12] 



closely identifiable with matter than tlv 

 variety, — a prevision of which fact was 

 sraspcd by lienjamin Pranklin long ago. ihi 

 difference in massiveness between the two kr 

 electricity enables electrical separation to go en ' 

 vacuo, and seems to me likely to be responsible for 



much of the energy of electrical separat- ' 



qucntly displayed in the earth's atmoi>|< 

 played most obviously when the nu^^.. 

 separated entities come together again. 



But what has all this to do with hydroi, 

 water ? Prof. Armstrong will not fail to I 



probably contemn, my caution in keeping ;;<i 



dry. 



But now to be incautious. If Prof. Armstrong has 

 qualms about supposing that rearrangements or 

 combinations of H,0 in a hydrone molecule can 

 effect electrical separation, I think those qualms are 

 judicious ; it would be too much like .seeking a 

 generation of one kind of electricity only. At the 

 same time, if any cause can be assigned which would 

 separate the opposite electricities of matter into 

 different regions of a globe, an enormous amount of 

 energy would be displayed, sufficient for baJl-Ught- 

 ning. The quantities dealt with are prodigious. But 

 where is such cause to be found ? Could the 

 opposite charges be centrifugalised apart ? Could 

 they, in rushing together, form a cyclone which 

 would keep them from collapsing together for a 

 time ? The speed required, to maintain a shell of 

 protons round a nuclear group of electrons, like a 

 sort of inverted large-scale atom, is not unreasonable. 

 A spherical vortex has been worked out by Prof. 

 W. M. Hicks ; what does he think of the suggestion ? 



I have no wish to enter the lists against the high 

 meteorological authority of Dr. Simpson, but I do 

 not feel that the last word has been said about the 

 electrical energy of thunderstorms. Nor do I suppose 

 that the last word has been said about what constitutes 

 a chemical molecule, nor yet about hydrone. 



Oliver Lodge. 



Salisbury, December 9. 



Industrial Research Associations. 



I HAVE read with much interest the article entitled 

 " Industrial Science " appearing in Nature of De- 

 cember I, and 1 would beg to thank you for pointing 

 out that the scheme of the Department of Scientific 

 and Industrial Research for the estabhshment of 

 Research Associations has not had a fair chance. 

 Few could have foreseen the difficulties which it has 

 encountered, and still fewer could realise what these 

 actually are unless engaged in industrial op>erations. 



As a firm believer in the ultimate success of the 

 co-operation of science w'ith industry, and as one who 

 has followed closely the initial stages of one of the 

 largest of the Research Associations, I should like 

 to add that I am convinced that the scheme in- 

 augurated by the Department is fundamentally a 

 good one, and in my opinion is hkely-to have a very 

 far-reaching effect, in helping our industries to face 

 with confidence the unusual difficulties of the present 

 situation, due no doubt in large measure to the lack 

 of appreciation in the past of the value of science to 

 industrj\ 



I am aware that there are many who do not 

 believe in the value of Research Associations, and 

 that recently it was suggested in another journal that 

 the " least direct way of helping industry by 

 science is the quickest : stimulate research at exist- 

 ing institutions," etc. I appreciate most thoroughly 

 the research work that is being done in the universities 

 and similar institutions, and I am in reality most 



