^ May\'],\'&li\ 



NA TURE 



55 



or other branch of Natural Philosophy, the competition being 

 open to all persons who have at any time been admitted to a 

 degree in the Unwersity of Cambridge, has been adjudged to 

 Kdward lohn Routli, M.A., F.R.S., St. Peter's College. The 

 subject of the essay is "The Criterion of Dynamical Stability." 

 The valae of the prize is about 250/. 



A Warden of Cavendish College in the place of the Rev. T. 

 J. Lawrence, resigned, will be elected on Tuesday, June 5. The 

 College is intended for students somewhat younger than ordinary 

 undergraduates, and the teaching and discipline correspond with 

 those of the higher forms in a public school. The sahiry is 

 500.'., or a capitation fee of 5/ when the number of students 

 exceeds 100. Candidates are requested to communicate wiili 

 the Rev. Prebendary Brereton, Little Massingham, Rougham, 

 Norfolk. 



Glasgow.— The Town Council has given a subscription of 

 5,000/. to the funds of the University of that city. 



Bristol. — It will be seen from our advertising columns that 

 a I'rincipal is wanted for University College. For so young an 

 institution the salary offered is veiy fair, and we hope that a 

 thoroughly good man will be obtained for the post, one who, if 

 not a man of science himself, at least regards it as of equal im- 

 portance with literature. 



SOCIETIES AND ACADEMIES 



London 

 45 g- Royal Society, April 12. — " On certain Molecular Changes 

 which occur in Iron and Steel during the separate acts of Heating 

 and Cooling," by Prof. Norris, M.D., Queen's College, Bir- 

 mingham. 



An exhaustive study of the various conditions has led to the 

 elucidation of the nature of liardening, softening, tempering, 

 annealing, &c., and has further shown that numerical values 

 may be assigned to these states. 



The research has further established the existence in steel and 

 in iron containing Jrcc carbon of a contraction or shortening 

 which is excited by heat, and which proceeds simultaneously 

 with the dynamical expansion, and masks its true amount. This 

 is divisible into ///;/< and I01.0 temperature contraction. 



The presence of a cooling expansion or crystallisation, which 

 conies in during the dynamical contraction, and masks its true 

 amount. 



These effects, due to crystallisation and decrystallisation, are 

 the causes of the so-called kicks, or temporary contractions and 

 expansions which occur during the heating and cooling of the 

 steel. 



That the low-temperature contraction and cooling expansion 

 are due to decrystallisation and crystallisation which occur 

 during the acts of heating and cooling, while the kicks them- 

 selves are simply the ihernnl effects associated with these 

 changes, and are proportionate to tlieir extent. 



That protracted annealing, that is, extremely slow cooling, 

 brings about molecular separation of the carbon and iron ; and 

 steel in such a state contracts greatly when higli temperatures 

 are reached, producing llie contraction returns seen at the end of 

 the heating, and which are due to the coiidemation produced by 

 the recombination of the carbon and iion. .Steels in this state 

 are less susceptible to cooling expansion (ciystallisation), and 

 therefore to low temperature contraction on suljsequent heating. 



April 26. — " Researches on Emeralds and Beryls. — Part II. 

 On some of the Processes Employed in the Analysis of Emeralds 

 and Beryls," by Greville Williams, F.R.S. 



" On the Nature and Origin of the Beds of Chert in the 

 Upper Carboniferous Limestones of Ireland," by Prof. Edward 

 HuU, M.A., F.R.S. , Director of the Geological Survey of Ire- 

 land. With "Chemical Notes," by E. T. Hardman, F.C.S., of 

 the Geological Survey of Ireland. 



From a review of the whole circumstances, it appeared that 

 the origin of the chert-beds was to be attributed to the replace- 

 ment of the original limestone or calcareous " ooze," due to 

 organic agency by silica, and that the rock is truly a pseudo- 

 morph, a view held by teveral observers. 



The manner in which this replacement had been brought about 

 was then touched upon. It was shown that there was reason 

 for believing that at the close of the period during which the 

 carboniferous limestone was formed over the area of Central 

 Ireland, the sea-bed was elevated so as to be covered by the 



waters of a shallow sea exposed to the sun's rays, and of a 

 warmer temperature than when at a greater depth. The waters 

 appear to have been charged with a more than usual supply of 

 silica in solution, derived (as Mr. Ilardman suggests) from the 

 surrounding lands, formed, for the most part, of highly siliceous 

 materials. As silica is less soluble than carbonate of lime, 

 chemical replacement would naturally take place, the carbon- 

 ate of lime being dissolved out and its place taken by the 

 silica. The warm condition of the sea-water, its exposure to 

 sunlight, the porous character of the corall ne, ciinoidal and 

 other forms, and the soft and "oozy" condition of the fora- 

 miniferal mud would give easy access to the sea-waters, and the 

 process of silicification would take rlace analogous to that 

 described by Dr. Martin Duncan, F.R.S., as having occurred in 

 the West Indies. 



Linnean Society, April 19. — G. Bentham, F.R.S., vice- 

 president, in the chair. — M. Cassimir De Candolle read an im- 

 portant paper on the geographical distribution of the Meliace.-e. 

 His general conclusions with regard to the Melia family may 

 thus'be summarised : (a) The number and the mutual aflinities of 

 the various genera of Meliacece decrease from the Asiatic region 

 towards Africa and America on one side and towards East'Poly- 

 nesia on the other ; (/<) Between the Meliaceo; of America and 

 Africa there exists analogy, whilst Polynesian species belong to 

 Indian type ; (c) New Caledonia contains within itself a remarkable 

 number of distinctspecies, the type of which, however, is Indian ; 

 ((/) in Australia three Indian genera are found, along with three 

 genera exclusively belonging to Australia ; (<■) No species of 

 Meliacere have hitherto been collected in the mosteastern islands 

 of Polynesia ; if subsequent observations reveal such it will be 

 interesting to know whether they pertain to Indian or American 

 type. — Another contribution on the geographical distribution of 

 the Indian fresh-water fishes (Part II. The Silurida;), read by 

 Dr. Francis Day, curiously enough in some ways points to a 

 similar conclusion to that derived from the plants above-men- 

 tioned. Dr. Day showed that of the twenty-six genera of Silu- 

 roida; represented in the Indian Empire, ten are found in the 

 Malay Archipelago, two more reach Cochin China or China, 

 whilst Clarias only is common to India and Africa, and more- 

 over it likewise is found in the Malay Archipelago. He infers 

 that the said freshwater fish of India are more closely related to 

 a Malayan than to an African fish fauna. — Mr. R. Irwin Lynch, 

 of Kew Gardens, brought before the notice of the Society some 

 observations on the disarticulation of the branches of Cuslilloa 

 elaslica, the caoutchouc tree of Central America. lie has noticed 

 that the lateral branches are detached from the ascending stem 

 of the plant in a regular manner from below upwards in the same 

 way as leaves, and this happens always at the point of insertion. 

 Ill certain Euphorbiaceous genera which have leaf-like'branches, 

 these fall as does a leaf, and they bear in their axils a bud from 

 which alone the permanent branches are produced. They are 

 themselves subtended by a leaf reduced to a scale. — Capt. 

 Chimmo followed by two communications, one concerning the 

 mode of obtaining and the structure of the so-called Euplectella 

 of the Philippines, the othe/' a description of a supposed new 

 Rhizopod. 



Anthropological Institute, May 8. — John Evans, F.R.S., 

 president, in the chair. — Special thanks were voted for the 

 present to the Lilirary of a complete set of the volumes relating 

 to the voyage of the Novara, published and presented by the 

 Austrian Government. — On an exhibition, by Mr. R. Biddulph 

 Martin, of objects from a large refuse heap in the neighbourhood 

 of Smyrna, Mr. Hyde Clarke, Col. Lane Fox, and the presi- 

 dent offered remarks. — Mr. A. L. Lewis communicated a de- 

 scription of the remains of a stone circle at Colderham, Kent, 

 illustrating his remarks by a well-prepared plan. — Dr. John Rae 

 read a paper on the skulls of the Esquimaux, attributing the fact 

 that two distinct types of skull exist among these peoples to an 

 admixture of blood. An interesting discussion followed, in 

 which Dr. Beddoe, Col. Lane Fox, and others took part. — Dr. 

 Beddoe, F.R.S., communicated a paper on the Aborigines of 

 Queensland, whom he described, on the authority of Mr. Chrisli- 

 son, who had had many years' knowledge of them, and employed 

 them very largely in sheep-farming, to be, in many respects, not 

 so black as they have been jiainted. 



Royal Microscopical Society, May 2. — II. C.Sorby, F.R.S., 

 president, in the chair. A number of donations to the society 

 were announced, including a sum of 500/. presented by Mr. C. 

 Lambert.lfrom a bequest of 25,000/. left by that gentleman's late 

 father, to be appropriated to benevolent and scientific purposes. 



