472 



NA TURE 



[March 14, 1895 



established. Olher tables show a close relationship between 

 the bright lines of the nebula and the dark lines in the so-called 

 Orion s!ar>, of which Rigel and Bellatrix are typical examples. 

 The following are the conclusions to which the investigation 

 has led : (l) The spectrum of the nebula of Orion is a com- 

 paund one, consistinj of hydrogen lines low temperature, 

 metal. ic lines and fluting=, and high temperature lines. The 

 mean temperature, however, is relatively low. (2) The spec- 

 trum is different in different parts of the nebula. (3) The 

 spectrum bears a striking resemblance to that of the planetary 

 nebulae and bright-line stars. (4) The suggestion, therefore, 

 that these are bodies which must be associated in any valid 

 scheme of classificaiion is streng'hened. (5) Many of the lines 

 which appear bright in the spectrum of the nebula, appear dark 

 in the spectra of stars of Groups II. and III., and in ttie earlier 

 stars of Group IV. ; a gradual change from bright to d.Trk lines 

 has been found. (61 The view, therefore, that bright-line stars 

 occupy an intermediate position between nebulx and stars of 

 Group III. is greatly strengthened by these researches. 



The Eclipse of the Moon. — The earlier phases of the 

 total eclipse of the moon on Monday morning were observed 

 under very favourable circums'ances in the neighbourhood of 

 London. The penumbra was not distinctly visible until about 

 ten minutes before contact with the shadow, and the whole disc 

 of the moon remained clearly visible, even at the middle of 

 totality, until clouds stopped observations about 4 a.m. The 

 parts deeply immersed in shadow were intensely red through- 

 out, and with the telescope all the principal foriraiions could 

 be easily distinguished. During totality the sky was excep- 

 tionally clear, and numerous ccculiationswereobserved without 

 difficulty. For half an hour after the commmcenient of totality 

 the following edge of the moon was pretty brightly illuminated, 

 and presented a striking contrast with the redness of the ad- 

 vancing etige ; at njid-cclipse, however, the whole of the disc 

 was veiy red. 



It is reported that nearly 140 observations of disappearances 

 or reappearances of eighteen stars were secured at the Royal 

 Obstrvatory on Monday morning by the eleven obseivers who 

 watched ihc progress ol the eclipse. 



The Nai'TIcal Alma.nac, 1898.— In the recently published 

 volume of the British Kphemeris for 189S, we note several 

 valuable additions. The places of eleven close circumpolar 

 .«lars, four of which are in the norlhetn hemisphere, are given 

 for each day of the year, and the mean places of fifty two 

 additional stars fur navigational purposes have been ad'led. 

 The improved explanations of the contents will also no duubt 

 be generally appreciated. The publication of an abridged 

 edition for the use of seamen is a step in the right direction. 



PHYSICAL WORK OF HERMANN VON 

 HELMHOLlZy 

 1 

 HTHE career we ate to consider this evening was a career of 

 singular distinction. In days when the range of " natural 

 knowledge" is so vast that most workers are compelled 10 be 

 content if they can add something to one or two of the sub- 

 divisions of i.ne of the main branches of science, von Helm- 

 holti showed us that it is not impossible to be at once a great 

 tnnthemaiician, a great experimenial physicist, and, in the 

 widest sen»e of the term, a great biologist. 



It was but eight months yesterday since he delivered his 

 last lecture ; it is six months to-day since he Hied, and the 

 interval is too short for us to attempt to decide on the exact 

 place which will I c assigned to him by posterity ; but making 

 all allowance for the fact that etch age is apt to place its own 

 great among the gteatesi, making all allowance for the spell 

 wbiih hs name cast over mmy ot us in the lectute-rooras where 

 we ourselves first gained some knowledge ol science, I am sure 

 thnt I only e\pre-s the vie*» of all those who know his work 

 he', when I jay that we place him in the very front rank of 

 those who have led the great scientific m'lvement of our time. 

 Tliis opinion I have now to juiiily. I must liy to convey to 

 you in sume >ixiy minutes an outline of the «ork of more than 

 lift y strenuous ) can, to give you some idea of the wide range 

 of the muhitold activities which were crowded into them, of the 

 marvellous insight with which the most diverse problems were 



1 A di^otiriw delivered at ihe Royal ln«tiluiion,by Prof. A. W. Rijcker, 

 r.R..S., on Friday, March 6. 



NO. 1324, VOL. 51] 



attacked and solved, and, if it may be, some image ot the man 

 himself. The task is impossible, and I can but attempt some 

 fragments of it. 



The history of von Helmhollz is in one respect a simple tale. 

 There are no life and death struggles with fate to record. His 

 work was not done with the wolf at the door, or while he him- 

 self was wrestling with disease. He passed through no crises in 

 which success or failure, immortality or oblivion, seemed to 

 depend on the casting of a die. He suffered neither from 

 poverty nor riches. He was a hale strong man on whom ex- 

 ternal circumstances neither imposed exceptional disabilities, 

 nor conlerrcd exceptional advantages, hut who, by sheer force 

 of the genius that was in him, passed on from success to suc- 

 cess till he was recognisei by all as the ailmirable Crichton of 

 modern science, the most widely cultivated of all students of 

 nature, the acknowledged leader of German science, and one of 

 the first scientific men in the world. 



It is the more fitting that this evening should have been set aside 

 for the consideration of the work of Flelmhollz, in that England 

 may claim some share in his greatness. Hefore her marriage his 

 mother bore an English name — Caroline I'enn ; she was, as her 

 name implied, of English descent. His father was a Professor 

 of Literature in the Gymnasium at Potsdam, so that his early 

 days were passed amid that plain living and high thinking which 

 are characteristic of intellectual circles in Germany. The boy 

 did well at school, and when lite time came for choosing a 

 profession, his passion for mathematics and physics h.id already 

 developed itself. The course of his love for these sciences did 

 not run quite smooth. The path of his ambition was crossed 

 by Ihe haid necessity which in some cases checks, in otheirs 

 fosters, but in all chastens the aspirations of youih. He had 

 to make his livelihood. Science must be to him what the 

 Germans happily call a "bread-study." Medicine ofi'ered a 

 fair prospect of prosperity. Physics, in those days, was but 

 an in'clledu.il pastime. And so Ihe young man took his 

 father's advice, and became an army doctor. In this, as in so 

 many other cases, "the path of duty was the way to glory." 



It is possible that if von Helmhollz had been what — with s 

 sad consciousness of the limitations it implies — t may call a 

 mere physicist, he would have played a greater part in the 

 development of some of those subjects, the study of which he 

 initiated or helped to initiate, but did not thereafter pursue. 

 It is possible ihat had he been a biologist, and nothing more, 

 he would have followed up the early investigation in which he 

 disproved the old theory that putrelaclion and fermentation are 

 chemical piocesses only, clearly indicating, if he did not 

 actually demonstrate, that the decay which follows death is doe 

 to an tiulbur-t of low forms of life. 



He might thus under other circumstances have done work for 

 which he showed his competence, but which is now chiefly 

 associated with other names ; but it is certain that without the 

 unusual combination of wonderful mathematical power and a 

 professional knowledge of anatomy, be would never have 

 .iccomplislied the special tasks which it is his special glory to 

 have af-hicved. 



His first three papers, however, hardly displayed Ihe fusion 

 between his various powers which was afterwards so remarkable 

 a characiciistic of his work. The first two were on biological 

 subjects. The third w.as ihe famous essay on the "Conserva- 

 tion of Force." I have told elsewhere the story of the 

 dramatic circumstances under which it was given to the world, 

 of the interest it excited among the members of Ihe Physical 

 Society of Berlin, Ihe refusal of the editor of Pi>i;f;tiidorll'f- 

 Annaltn to publish it, and the final triumph of Ihe author and 

 his views, {/'orlniglilly Kdir.v, November 1S94.) Helmholli 

 was not, and did not claim lo be an original author of the 

 doctrine of the con.servation of energy ; but two young men. 

 Sir William Thomson in Englaml, and Melmholtr. inGermaDT^ 

 indeptndenlly, and within a month of each other, were tM 

 first persons who compelled the scientific world to regard it 

 seriously. 



Thee is one interesting fact which connects this essay 

 diiectly with the Royal Insliiuiion. Four years alter it was 

 puldislcd, i' was placed by Hu Bois Kcynond in the hands of 

 one who was lost to ^cicnce in the same year as von Helmliollr 

 h msell — the lale Piol. Tyndall. Me was much impressed, and 

 has sp< ken o( ihc incident as bringing him face to Incc with the 

 great doctrine of the " Consetvniion of Knergy." {" Intioduc- 

 lirn 10 Popular Lectures by Helmholt?," translated by E. 

 Atkinson, 1873.) He translated the essay into English, and 



