November 7, 1895] 



NATURE 



II 



gravest problems that man has to grapple with ; and 

 secondly, in that it has more or less distinct reference to 

 a past of which the present is but an outcome and a 

 development. C. Lloyd Morgan. 



HERMANN HELLRIEGEL 



PROF. HERMANN HELLRIEGEL, whose death 

 took place at Bernburg, Anhalt, on September 24 

 last, was born at Pegau, Saxony, on October 21, 1831, so 

 that he was within a month of completing his sixty- 

 fourth year. His life, on the whole, was uneventful, for 

 he devoted himself with studious zeal almost entirely to 

 investigations, both chemical and physiological, into the 

 l)henomena of plant nutrition. One of his earliest 

 official posts was that of Director of the Agricultural 

 Experiment Station at Dahme, in Brandenburg, which 

 was founded in 1857 by an association of agriculturists in 

 Jiiterbog-Riickenwalder. During his tenure of this post 

 he studied experimentally the alimentary needs of certain 

 plants which are cultivated as field crops, notably cereals, 

 potatoes, and sugar-beet, his method involving the use of 

 sterilised soil, both by itself and with the addition of 

 various chemical salts. His physiological inquiries em- 

 braced observations on the growth and development of 

 roots, on the quantity of water used in the growth and 

 maturation of field crops, and on the minimum amounts 

 of nitrogen, phosphoric acid, potash, and other in- 

 gredients required by plants. Supplemented by observ- 

 ations on crops grown in the open field, these investi- 

 gations led Hellriegel to conclusions of great practical 

 importance, notably in connection with sugar-beet, a crop 

 which Germany grows more extensively than any other 

 European country, its annual average area for the last 

 twelve years having been 800,000 acres, or more than one- 

 fourth of the entire European acreage. 



It was with no little regret that in 1873 Hellriegel gave up 

 his directorship at Dahme, though for a post with greater 

 emoluments. But his capacity as an investigator had made 

 its mark, and when in 1882 the Verein fiir Zucker- Indus- 

 trie, in co-operation with the Government of the Duchy of 

 Anhalt, established an experimental station at Bernburg, 

 for the special investigation of problems bearing upon 

 the cultivation of sugar-beet, it was felt that Hellriegel 

 possessed special and peculiar claims to the directorship, 

 which was accordingly offered to him. He accepted with 

 avidity a post which enabled him again to devote his 

 time and energy solely to those investigations into plant- 

 life, which had previously exercised upon him so strong a 

 fascination. The station at Bernburg is admirably 

 equipped, and Hellriegel found himself in a position to at 

 once resume his inquiries into the nutrition of leguminous 

 plants, a subject that had previously received his atten- 

 tion at Dahme. It was here that after a dozen years' 

 work he, in collaboration with Dr. Wilfarth, made the 

 y^reat discovery with which his name will ever 

 l)e inseparably associated, namely, the capacity of 

 leguminous (or at least of papilionaceous) plants to take 

 up, or fix, through the agency of the micro-organisms of 

 their root-nodules, the free or uncombined nitrogen of the 

 atmosphere. 



The intimation — the revolutionary announcement — 

 of this startling discovery was made on September 

 20, 1886, in a communication to the Naturforscher 

 \'ersammlung, held at Berlin, and over the agricul- 

 tural chemistry section of which Dr. (now Sir Henry) 

 (Gilbert happened to be presiding— a coincidence of 

 exceptional interest in view of the circumstance that 

 Sir Henry Gilbert was one of the joint authors of the 

 ( clebrated memoir by Lawes, Gilbert, and Pugh, " On 

 the sources of the nitrogen of vegetation, with special 

 reference to the question whether plants assimilate free 

 or uncombined nitrogen" {Phil. Trans. 1861), which, at 



NO. 1358, VOL. 53] 



the time of its appearance, and for long after, was re- 

 garded as setting at rest the question as to the capacity 

 of plants to assimilate the free nitrogen of the atmo- 

 sphere, and of confirming upon this point the negative 

 results previously obtained by Boussingault. Hellriegel'* 

 momentous discovery furnished an explanation of the 

 long-known fact that a clover-crop leaves the soil richer 

 in nitrogen than it finds it, and is therefore a suitable 

 crop to precede the wheat-crop in a rotation, clover 

 being — as we now understand through Hellriegel's dis- 

 covery — a nitrogen-accumulating plant, and wheat a 

 nitrogen-consuming one. Indeed, the fact itself is a very 

 old one, for it was observed by the farmers of the Roman 

 Republic that beans, lupins, vetches, and other plants 

 belonging to the sub-order Papilionacea;, as now defined,, 

 rendered the soil " more fruitful " for the crops that fol- 

 lowed. But nearly 2000 years elapsed from the time when 

 Varro recorded this, to that when Hellriegel, a brief nine 

 years ago, supplied the explanation. It in no way de- 

 tracts from the value and significance of the discovery 

 that Hellriegel and Wilfarth should have happened upon 

 it in thecourseof investigations which were really directed 

 to quite a different object. Those who devote their lives 

 to research are not unaware that gems, hitherto unseen^ 

 may sometimes be picked up on the wayside. 



We have spoken of Hellriegel's discovery as revolu- 

 tionary, and it certainly upset a long-cherished belief. 

 The opposition which his announcement received at the 

 outset was a testimony to its importance. Subsequent 

 research, both in Europe and in North America, has» 

 however, only strengthened the position which Hellriegel 

 took up, whilst it has suggested new lines of investiga- 

 tion for which there will probably be no lack of workers. 

 Brdal, Frank, Hiltner, Lawes and Gilbert, SchlcEsing 

 fils and Laurent, are but a i&w of the investigators wha 

 have proved the accuracy of the discovery made at 

 Bernburg. In recognition of his work, Hellriegel was 

 elected an honorary member of the Royal Agricultural 

 Society of England, a rare distinction, which he enjoyed 

 in common with such continental workers as Pasteur, 

 Fleischmann, and Chauveau. In France his merits 

 were recognised by his election as a foreign associate of 

 the Socidte nationale d'Agriculture, and as a Corres- 

 pondant of the Academy of Sciences. 



NOTES. 



The German committee for the exploration of the South 

 Polar regions met at Berlin on Sunday, and decided to send two 

 vessels southwards from Kerguelen Island, leaving full liberty of 

 action to the leaders. The total sum to be allotted for the expe- 

 dition, which is to last three years, has been fixed at 950,00a 

 marks (;^47.5oo)- 



Chicago University continues to be the recipient of For- 

 tune's favours. Mr. John D. Rockefeller has (says the New 

 York correspondent of the Daily Chronicle) added ;,^200,ooo to 

 his previous gift of ;^8oo,ooo for the endowment of the Chicago 

 University, He promises ;if400,ooo more if any one else will 

 subscribe a like sum. When will the day come for such generous, 

 gifts to education and research in England ? 



The Municipal Council of Arbois, the birthplace of Pasteur^ 

 has decided to erect a statue to his memory, and also to call 

 the municipal college the Pasteur College. 



M. Berthelot, the distinguished chemist, has been appointed 

 Minister of Foreign Affairs in the new French Cabinet. He 

 was Minister of Education in the Cabinet of 1886-87. 



It is reported that the Paris Municipality have granted ;^8oa 

 to the Salpetriere Hospital for the erection of new buildings in 

 which to treat nervous and mental affections by electricity. 



