December i, 1910] 



NATURE 



145 



lemist. Theoretical contributions to this branch of 

 >rience are comprised in a series of papers on " The 

 Possible Significance of Changing Atomic Volume," in 

 which he suggests a relation between the energy of the 

 atoms and their compressibilities. In order to test his 

 hypothesis, he has made a long series of investigations on 

 the compressibility of elements and compounds. He has 

 determined this constant for nearly all the solid and liquid 

 ' ments, and he has shown that the compressibility is a 

 . riodic function of the atomic weights. In electro- 

 chemistry Prof. Richards has made important determina- 

 tions of the electro-chemical equivalent of silver, and he 

 has supplied some of the most rigorous proofs of the 

 universality of Faraday's law. 



Darwin Med.al. 



To Mr. Roland Trimen, who was for many years 

 rator of the South .African Museum in Cape Town, the 

 I irwin medal has been awarded. His official position, 

 .d the duties it involved, enabled him to do admirable 

 irk in African zoolog\\ His name will always stand 

 with those of Bates and Wallace in the establishment and 

 illustration of the theory of mimicry. In addition to his 

 researches on that subject, he has done admirable 

 ^tematic work, his descriptions of insects, especially the 

 ■pidoptera rhopalocera, being models of accuracy and 

 •;-rary style. He, furthermore, rendered the . greatest 

 distance to Charles Darwin, especially in his work on 

 orchids — assistance the high value of which is acknow- 

 ledged in a long series of that great naturalist's published 

 letters. 



Sylvester Med.al. 



The medal which perpetuates the name and mathe- 

 matical prowess of James Joseph Sylvester has this year 

 been assigned to Dr. Henry Frederick Baker, in recogni- 

 •in of his work in the theory of functions, wherein he 

 IS shown himself to be a profound analyst. His book 

 on the Abelian functions, published in 1897, is a classic, 

 and probably no better guide to the analytical develop- 

 ment of pure mathematics has appeared during the last 

 three-quarters of ^ century. While basing the argument 

 of the work on the methods of Riemann, he never loses 

 sight of the arithmetical ideas which w'e owe to Kronecker, 

 Dedekind, and Weber, or of the geometrical notions 

 l)rought to light by the labours of Clebsch, Gordan, 

 Noether, and Klein. The critical insight which was thus 

 In evidence marked him out a few years ago as the editor 

 of " Sylvester's Collected Papers." This work, which, 

 with the approaching issue of the fourth and last volume, 

 may be said to be complete, has been necessarily a difficult 

 task, which, besides making demands upon the resources 

 of an accomplished mathematician, has entailed no little 

 editorial labour. Dr. Baker, by explanatory and critical 

 '^^>servations, and by frequent ameliorations of the text, 

 iS done much to assist mathematical students. His 

 holariy work has resulted in a faithful record of the 

 urse of Sylvester's thought. It seems eminently fitting 

 at the Sylvester medal should be given to one who has 

 ^cted so lasting a memorial to the great mathematician. 



Hughes Medal. 



To Prof. John Ambrose Fleming the Hughes medal has 



'^^en awarded. For thirty years he has been actively 



igaged in researches in experimental physics, chiefly in 



•; technical applications of electricity. He was an early 



vestigator of the properties of the glow lamp, and 



ucidated the unilateral conductivity presented in its 



partial vacuum between glowing carbon and adjacent 



metal, a phenomenon which has been linked up recentiv 



^vith the important subject of the specific discharges of 



-ctrons by different materials. He has published in the 



ientific and technical Press, and in technical text-books, 



any admirable experimental investigations and valuable 



xpositions in the applications of electricity, as, for 



ample, to electric transformers and wireless telegraphy. 



': special interest and value for theory were the important 



^ults concerning the alterations in the physical proper- 



s of matter, such as the remarkable increase in the 



ctric conductivity of metals when subjected to very low 



mperatures, which flowed from his earlv collaboration 



NO. 2144, VOL. 85] 



with Sir James Dewar in investigating this domain. In 

 recent years he has taken a prominent part in the scientific 

 development of telegraphy by free electric waves. 



In the evening the fellows and their guests dined 

 together at the Whitehall Rooms, Hotel Metropole. 



ENTERIC FEVER CARRIERS.' 



'X' HE frequent difficulty in accounting for the source 

 ■•• of iniection of enteric fever once led to the 

 theory that this disease could arise de novo, that is to 

 say, that certain organisms in human dejecta were 

 capable of developing, in favourable circumstances, 

 into enteric fever organisms. It has also been main- 

 tained more recently that the specific organism of 

 this disease was capable of living and multiplying in 

 water and soil, for considerable periods. But the bac- 

 teriological work of the past few years has discredited 

 both these hypotheses; and the "carrier" case of 

 enteric fever or the mild, unrecognised case of infec- 

 tion generally, explain the transmission of the disease 

 in those cases in which the disease crops up in the 

 absence of any recognised sufferer from the disease. 



A "carrier" of enteric fever is" a person who," 

 although he may be in good health, carries the in- 

 fectious material in his body, from which it may pass 

 out. He is not merely a passive transmitter of infec- 

 tion ; he is also a breeding-ground and storehouse of 

 these specific organisms ; and it appears that not only 

 those sick with the fever, but also healthy persons 

 who happen to be "carriers" of the infection, offer 

 the best explanation for the maintenance of the in- 

 fection in communities. 



The subject has naturally attracted much attention 

 and led to many investigations, the results of which 

 are to be found in numerous recent publications,' and 

 Dr. Ledingham has done a great service in preparing 

 for publication a summan.- of the more important 

 investigations that have hitherto been made of this 

 subject. He gives the history of a large number of 

 occurrences of enteric fever in domestic life, in insti- 

 tutions, and in militar\- populations, in which the 

 source of infection has been traced more or less con- 

 vincingly to a "carrier." In many of these cases the 

 evidence is conclusive that the infection was conveyed 

 by food or milk. The recorded instances go to prove 

 that the female sex is more liable to carry the infec- 

 tion than the male, and that of both sexes some 2 to 4 

 per cent, of previous sufferers may continue to harbour 

 the germ, and become "carriers," who intermittently 

 discharge the germ, for periods extending maybe for 

 many years. 



As Dr. Theodore Thomson, who writes an intro- 

 duction to this report, states, the difficult\- of dealing 

 with "carriers" is ver\- great indeed, having regard 

 more particularly to the long periods durinof which 

 people may harbour the infection and to the fact that 

 it has hitherto proved ven,- difficult to free them from 

 the infection. The chief available measures include : 

 all possible efforts to detect "carriers" in the com- 

 munit\% and to endeavour to secure on the part of a 

 " carrier " those precautions of strict personal cleanli- 

 ness and of disposal of dejecta that will minimise the 

 risk of infecting others ; an endeavour must also be 

 made to prevent such "carriers" from taking anv 

 part in the milk trade or in the preparation or hand- 

 ling of food. 



In this interesting report. Dr. Ledingham also dis- 

 cusses the diagnostic methods employed in the search 

 for "carriers" and the immunitv question in "car- 

 riers." .\ useful bibliography is appended. 



1 Dr. J. C. G. Ledingham's Rexwrt to the Local Government Board on 

 the Enteric Fever "Carrier" ; being a Review of current knowledge on this 

 subject. Pp. 138. (London : Wyman and Sons, igio.) Price is. 



