48 



NATURE 



.[October 7, 19 15 



and in his experiments being- arrested in their 

 development. 



The intensity of the radiation is important, 

 and G. Fabre,* using- Linum catharticuni 

 as test plant, was able to obtain increased de- 

 velopment and germination of seedlings by work- 

 ing with emanations up to I'f, microcuries per 

 2 litres of air, and to retard development by using 

 emanations of 40 microcuries per litre of air. 

 H. Molisch^ obtained a like result: young plants 

 of vetches, beans, sunflower, etc., were stimulated 

 in growth by weak emanations, but checked or 

 entirely stopped by stronger ones. He further 

 claimed that the " rest period " could be broken by 

 the radium emanation, and forced lilac into bloom 

 in November by attaching pipettes containing 

 small quantities of radium chloride to the terminal 

 buds.^ In his earlier experiments he, like Di-.<on 

 and Wigham, failed to detect any radiotropism, 

 but later on he found indications in the case of 

 certain heliotropically sensitive plants, e.g., oats 

 and vetches.'^ 



These and similar results naturally suggested 

 that the residues left after the extraction of 

 radium, but still containing radioactive material, 

 might have definite manurial value, and it was 

 not long before definite statements were forth- 

 coming. Baker 8 claimed that increased yields 

 of wheat and radishes had been obtained by mix- 

 ing one part of radioactive material (2 mg. ra. 

 per ton) with ten of soil. It is true that Stok- 

 lasa's^ results were negative (although in his 

 other experiments radium emanations increased 

 growth to a marked extent), but this did not pre- 

 vent the introduction of radioactive fertilisers, 

 and the enterprising syndicates and companies 

 concerned were by no means loth to push their 

 wares. The staffs of the agricultural experiment 

 stations being busy people and, moreover, some- 

 what sceptical about plant stimulation on account 

 of some rather sad failures, did not generally take 

 the matter up, and it remained for Mr. Martin 

 Sutton to carry out the necessary tests. 



Mr. Sutton's experiments were made with 

 radishes, tomatoes, potatoes, onions, carrots, and 

 marrows, some grown in pots, others in plots out 

 of doors. Eight different radium residues were 

 used, in addition to pure radium bromide ; the 

 dressings were so arranged that equivalent quan- 

 tities of radium were given in each case (1/4000 

 mgm. radium bromide to 15 lbs. of soil in the 

 pots ; 2| times this amount per square yard to 

 the plots). Controls were set up, including a set 

 treated with the other substances present in the 

 residues, designed to ascertain whether those had 

 any effect. 



The results have just been issued by Mr. Sutton. 

 Going carefully through them, one is forced to the 

 conclusion that the radioactive materials have 

 been ineffective. In no case is there any clear 

 evidence of increased growth. Even the pure 



4 Comfit. Rend. Soc. BioLi^arxs.), 1911, Ixx., 187-18?. 



f' Uinschau. 1913. xvii., 95-98. 



•> Oesterr. Gart. Ztg., igi'. vii., 197-202. 



7 Sitzber. k. akad. uiiss. (Vienna), 191 r, cxx., 305-31S. 



** Jonrn. Roy. Soc. Arts, igx-^. Ixii., 70-78. 



9 Chent. Ztg., 1914, xxxviii., 841-844. 



NO. 2397, VOL. 96] 



radium bromide seems to have done nothing-. 

 We are therefore left with an apparent dis- 

 crepancy. The work of the physiologists, assum- 

 ing it to be sound, certainly indicated that radium 

 emanation is capable of stimulating certain cell 

 activities. Mr. Sutton's results show that such 

 stimulus, if it exists at all, does not affect the 

 final growth of the plant. The discrepancy is not 

 a new one, it is periodically confronting the agri- 

 cultural investigator. Thus Dr. Winifred 

 Brenchley, at Rothamsted, has failed to obtain 

 increases in growth by supplying plants with in- 

 organic poisons which have been supposed , to 

 stimulate certain cell functions in suitable dilu- 

 tions. The result opens up the prospect of an 

 Interesting discussion, but It also shows the danger 

 of arguing from a simple physiological observa- 

 tion to a complex phenomenon like the growth of 

 a plant in soil. E. J. Russell. 



PROF. E. A. MINCHIN, F.R.S. 



IT is with profound regret that we announce 

 the death, on September 30, at Selsey, of 

 Prof. E. A. Minchin, F.R.S. 



Edward Alfred Minchin, younger son of 

 Charles N. Minchin by his wife Mary J. Lugard, 

 was born in 1866. From his birth he suffered 

 from a constitutional weakness, and indeed 

 his life was despaired of at first. He grew 

 stronger with age, yet the premature close of his , 

 career was no doubt due to the physical disabili- 

 ties against which he had so bravely struggled | 

 to the very end. Unable to share in the rough 1 

 life of the ordinary schoolboy, he was educated 1 

 privately, and then for a short time at the United 

 Service College, Westward Ho ! When about 

 fourteen years of age he went to the Bishop , 

 Cotton School at Bangalore after having joined 

 his parents' in India. Here he lived happy years, 

 free to indulge to his heart's content that love 

 of animals and of natural history of which he 

 had already shown signs In his childhood, some- 

 times to the consternation of his nurse. He 

 made valuable collections, and developed early 

 his keen powers of observation. 



Although Minchin had distinguished himself 

 at school by his aptitude for the classics, it was 

 to natural science that he devoted himself in his 

 university career at Oxford. He obtained an 

 exhibition at Keble College, and took his degree 

 in 1890 with first-class honours in zoology. 

 Shortly afterwards he was awarded the Univer- 

 sity Scholarship at Naples, and then the Rad- 

 cliffe Travelling Fellowship. In 1893 he was 

 elected Fellow of Merton College. He was thus 

 enabled to travel abroad to pursue his researches 

 in foreign marine zoological stations, and to 

 work in the laboratories of Prof. Biitschli, in 

 Heidelberg, and Prof. R. Hertwig, In Munich. 

 For several years assistant to Sir Ray Lankester 

 and demonstrator in comparative anatomy at 

 Oxford, he afterwards became lecturer in biology 

 at Guy's Hospital, but soon succeeded Weldon 

 in the Jodrell chair of zoology at University 

 College, London, in 1899. 



