56o 



NATURE 



[January i6, 19 13 



in space. Even his explanation of the colours of thin 

 films is defective. Moreover, he was hopelessly at 

 sea, and, it may be observed, so was Huygens, in 

 attempting- to explain the absorption of light. Neither 

 of them had at his command any mechanism but that 

 of the collisions between particles of asther, particles 

 of matter, and light corpuscles, and they could but 

 juggle with the relative sizes of these things. Newton 

 was very hard put to it to explain the difference be- 

 tween a perfectly transparent body and a perfectly 

 black one, and was compelled to suppose it due to a 

 small difference in the sizes of the particles of matter. 

 Huvgens would have liked to ascribe internal 

 reflections at the surface of a piece of glass to colli- 

 sions between the aether corpuscles and the particles 

 of air outside, and was disconcerted by the fact that 

 reflection took place equally well when there was no 

 air at all. But it is quite unnecessary to follow the 

 subject further, and discuss the contributions of Young 

 and Fresnel, and the other men of famous names to 

 whom the modern theories of radiation are due. 



The point is simply this, that each of these great 

 workers constructed for himself a hypothesis or model, 

 which represented correctly certain facts known to 

 him, and by its aid was able to use what he Rnew as 

 a means to learn more. The results of his work de- 

 pended upon the construction of his model, and his 

 choice of "the known facts he had made it to represent 

 to a greater or less degree. For no one could con- 

 struct a hypothesis which represented correctly all that 

 was known. But if it was correct so far as it went 

 it led to good results in a limited field. 



Therefore it happens that hypotheses must always 

 be diversified, and it is well for the possibilities of 

 advance that they should be. If now we have a 

 number of new facts regarding new radiations, if it 

 turns out that they are to be carried over to the older 

 radiations which have been studied for so long, and 

 if the wave theory cannot absorb them at once, this 

 means no rejection of the work of the past, no re- 

 tracing of steps. It means rather the enriching of our 

 opportunities of advance, in which all the good work 

 which has been done in the past will tell as well as 

 that whicli we may hope to do in the future. 



If mv observations are well-worn sayings, you will 

 perhaps forgive the fact in the newness, and I 

 should like to add, if I might, the appropriateness, of 

 the illustration. It does, after all, make for our 

 encouragement and efficiency if we remember that 

 we are free to make any hypothesis we please, and 

 that we are not to be judged directly for the choice 

 we make, but indirectly for the use we make of it. 

 Our reasons for choosing a scientific creed wi!I prob- 

 ably be wrong; we cannot hope to do better always 

 than Newton and Huvsrens. But perhaps we ran do 

 something with it which will be good and will last. 

 It mav contribute also to the general peace if we 

 remember that our hypotheses are made, in the first 

 instance, for our own personal use, and that we have 

 no justification for demanding that others shall adopt 

 the means which we find most convenient in the 

 modelling of our own ideas. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — The professor of anatomy has re- 

 appointed Dr. W. L. H. Duckworth to be senior 

 demonstrator of human anatomy for five years from 

 January i, 1913, and Mr. D. G. Reid to be an addi- 

 tional demonstrator of human anatomy for the same 

 period. 



The Quick professor of biology has reappointed Mr. 

 C. Warburton to be demonstrator in medical ento- 



mology as from October i, 1912, to September 30, 



1915- 



The managers of the Balfour Memorial Fund give 

 notice that the Balfour studentship will be vacant 

 March 25. The names of applicants, together with 

 such information as they may think desirable, should 

 be sent on or before January 31 to the secretary. 

 Prof. J. Stanley Gardiner, Zoological Laboratory, 

 Cambridge. 



Oxford. — The master and fellows of University 

 College intend to proceed, in the course of the Hilary 

 Term, 1913, to the election of a fellow qualified to 

 take part in the educational work of the college as 

 praelector, with special reference to the chemistry 

 schools, provided that a candidate suitable to the re- 

 quirements of the college presents himself. Candi- 

 dates must have taken a degree in a university of the 

 United Kingdom or of the British Dominions beyond 

 the Seas, and be unmarried. A stipend of at least 

 350Z. per annum, including the emoluments of the 

 fellowship, will be assigned to the fellow and prae- 

 lector, so appointed, from the first, with prospective 

 rise of salary proportionate to nature and length of 

 service. The praslector in chemistry will not be pre- 

 cluded from undertaking further work in the Univer- 

 sity, outside the college, subject to the consent of the 

 master and fellows from time to time. Candidates 

 are requested to forward to the master of University 

 College, on or before January 31, 1913, the following 

 documents : — (i) A signed application setting forth the 

 candidate's qualifications, and any evidence (such, 

 e.g. as original work) which he may desire to lay 

 before the " electors ; (2) three, and not more_ than 

 three, testimonials from independent sources "in his 

 favour. 



Prof. R. M. Burrows, professor of Greek in the 

 University of Manchester, has been appointed prin- 

 cipal of King's College, London, in succession to the 

 Rev. Dr. .'\.' C. Hea'dlam. 



The fifth annual dinner of old students of the Royal 

 College of Science, London, will be held at the Caf6 

 Monico, Shaftesbury Avenue, on Saturday, January 

 25. The president of the Old Students' Association 

 (Sir William Crookes, O.M., F.R.S.) will preside, 

 and the guests will include Sir Alfred Keogh, K.C.B., 

 Sir Henrv Miers, F.R.S. , Sir Robert Morant, K.C.B., 

 Lieut.-Col. Sir David Prain, CLE., Sir Amherst 

 Selbv-Bigge, K.C.B., Dr. R. T. Glazebrook, F.R.S., 

 and Dr." H. Frank Heath, C.B. Tickets may be- 

 obtained on application to Mr. T. LI. Humberstone, 

 secretary of the Old Students' Association, 3 Selwood 

 Place, South Kensington, S.W. 



The recently established University of Hong Kong 

 is making rapid strides in the development of its- 

 various faculties, and attention is at present being 

 specially directed to the provision of facilities for the 

 practical study of pure and applied science. In an 

 address delivered to the Institution of Engineers and 

 Shipbuilders of Hong Kong last November, Prof. 

 C. A. M. Smith, professor of engineering in the new- 

 University, made an eloquent appeal to men of wealth: 

 to assist in the important work of training Chinese 

 students in modern science. " In Hong Kong," he 

 said, " we wish to train men who know the East to 

 develop China's natural resources. For that develop- 

 ment they must obtain machinery — if we do our work 

 aright we shall secure a market for those who are 

 at home, and provide greatly increased freightage for 

 the shipping to this port." Later he continued : — 

 "We require at once machines for demonstration and" 

 exnerimental purposes. We want to equip labora- 

 tnrif^s for testing the materials of construction, such 



NO. 2255, VOL. 90] 



