1 66 



NATURE 



[April 8, 1920 



demonstrated during the war that scientific men who 

 from motives of patriotism accepted a low scale of 

 salary for their services in Government Departments 

 were accorded an equally modest official status. 



The ultimate basis on which an adequate recogni- 

 tion of the importance of the scientific technical expert 

 must rest will be the estimation in which science and 

 scientific research are held by the great mass of 

 intelligent men and women. It must be realised, in 

 the first place, that a training in science on the right 

 lines and under the right men will be as efficient in 

 broadening the outlook on the world and stimulating 

 the imagination of the student as a detailed study 

 of the vicissitudes of ancient wars or the eccentricities 

 of Greek and Latin irregular verbs. It must also be 

 recognised that no course of science can be con- 

 sidered complete unless it has included a session at 

 least spent in scientific research, humble though it 

 may be and directed by more experienced workers. 

 But it must be genuine research, not merely a 

 "heuristic" imitation of the real thing. 



The more science graduates who have learnt to 

 understand what research means there are scattered 

 about the country — in factories, in counting-houses, in 

 Government offices, in educational establishments of 

 every kind, and, most important of all, in municipali- 

 ties and legislative bodies — the wider will be the 

 recognition of the value of science. 



Unfortunately, scientific studies are seriously handi- 

 capped in the competition for university students by 

 the fact that the fees are, as a rule, distinctlv higher 

 than those for arts. There is, therefore, a strong 

 pecuniary inducement for parents to select an arts 

 rather than a science curriculum for their children. 

 Such a handicap is obviously opposed to the national 

 interest, and should not be allowed to continue. 



In view of the urgent reasons for associating 

 research with higher scientific education, it is to be 

 regretted that the general tendency of Government 

 policy should be to divorce industrial research from 

 the universities and to place it in the hands of asso- 

 ciations of commercial firms. The discoveries that 

 open up new lines of development in great manufac- 

 turing industries are arrived at by processes essentially 

 similar to those that lead to advances in pure science, 

 and if we are to get the best results it will be by the 

 co-operation of the vigorous university life which 

 has sprung up in recent years at so many centres in 

 busy industrial districts with the commercial enter- 

 prise in its vicinity. 



Finally, if we are to secure to science its full weight 

 in the councils and policy of the countrv, we must not 

 confine our propaganda to the "governing" or upper 

 classes, or to the ranks of professional workers, or 

 to those engaged in commercial pursuits, but we must 

 develop by all the means in our power a love of 

 science in the great army of the manual operatives, 

 whom it would seem that in a not distant future we 

 shall, willingly or unwillingly, have to acknowledge 

 as our masters. With their increased leisure there 

 should be no difficulty in enlisting a large contingent 

 of men and women who will be interested in science, 

 either for its own sake or for its value in enabling 

 them to understand the meaning of the work in which 

 they are engaged. Some of them will in all probabilitv 

 definitely ernbrace a scientific career, and in this they 

 should receive every assistance and encouragement, 

 while others will render no less service as amateurs 

 and as missionaries of science among their -fellows. 

 Already, I am told, a great deal is being done in this 

 direction in connection with University College, Not- 

 tingham, and no doubt much is being accomplished 

 on similar lines at the Midland and Northern uni- 

 versities. At present the operations of the Workers' 

 NO. 2632, VOL. 105] 



Educational Association are largely confined to the 

 somewhat restricted domains of constitutional law and 

 history and political ecenomy, but a few years may 

 see a great development of more stimulating and 

 attractive studies in the broad realms of science. 

 March 31. John W. Evans. 



The Secondary Spectrum of Hydrogen. 



The recent investigation by Dr. Merton of the effect 

 of an admixture of helium on the intensity distribu- 

 tion in the hydrogen spectrum appears to have given 

 a very strong clue towards the elucidation of that 

 spectrum. On the photographs taken by Dr. Merton 

 (reproduced in part in Proc. Roy. Soc, October, 

 19 19) the spectra appear completely different in 

 the cases of pure hydrogen and of hydrogen mixed 

 with helium. Many lines, in the first case quite 

 strong, are totally absent in the second ; others remain 

 practically unaltered in intensity; while a third set 

 appears in the second case, though practically or 

 completely invisible in the first. Such results seem, at 

 first sight, to point to the existence of at least three 

 classes of lines which are mutually independent, one 

 class being unaffected by helium and the others 

 affected in opposite senses. 



A somewhat exhaustive investigation which I have 

 made recently in regard to these photographs, kindly 

 lent to me by Dr. Merton, and the previously pub- 

 lished tables of the spectrum has convinced me, how- 

 ever, that this interpretation is not the correct one. 

 It was known already that the secondary spectrum 

 of hydrogen contained two sets of lines, one showing, 

 and the other not showing, the Zeeman effect. A third 

 and doubtful set were abnormal in regard to the 

 Zeeman effect. Dufour examined many of the strong 

 lines in the spectrum, and, although his investigation 

 needs still to be extended much further, a considerable 

 amount of exact knowledge of individual lines is 

 available. 



Fulcher also had previously investigated the low- 

 potential discharge in hydrogen, and isolated two band 

 spectra peculiar to this discharge, which spectra we 

 may call the Fulcher bands. They differ from more 

 ordinary bands in their large component separations, 

 and their most important part is in each case a set 

 of triplets which recur towards the red end. Although 

 they do not readily fit the Deslandres type of formula, 

 I have been able to establish a mathematical relation- 

 ship between the two bands, from which it appears 

 that they must be considered jointly as one band. 

 In addition to the triplets there are many associated 

 sets of single lines, which Fulcher considered, on 

 experimental grounds, to belong to the same band 

 system. 



Dr. Merton 's results have made a valuable con- 

 tribution which enables us to isolate these Fulcher 

 bands completely from the rest of the spectrum. 



The conclusions at which I have already arrived 

 mav be summarised as follows : — 



The secondary spectrum of hydrogen consists of a 

 set of band spectra — how far divided into sets which 

 are mutually independent in the mathematical sense 

 is uncertain, but at least partially so divided — 

 together with a superposed spectrum of single lines. 

 The band lines are those which show no Zeeman 

 effect, and the lines of the superposed spectrum all 

 show the Zeeman effect. This general statement still 

 requires considerable experimental work to establish 

 its complete truth, but the evidence so far available 

 is sufficient to leave little doubt in the matter. 



Dr. Merton 's spectra, taken in the presence of 

 helium, preserve what I have called the superposed 



