334 



NATURE 



{Feb. 26, 1874 



side of which is the collodionised plate which fits water-tight 

 aeainst the other sides by means of india-rubber packing. There 

 is a tube passing into this box tlirough which first the ordinary 

 silver solution is poured, and then by laying the collodionised 

 plate downwards it is covered by thesolution and sensitised ; this 

 is then drawn off, and the box, which is contained in a suitable 

 holder, placed on the telescope and exposed by drawing away 

 the non-actinic glass cover in front. After exposure the 

 coloured glass is replaced, the box removed and developed by 

 pouring-in the solution in the same manner as the silver, in the 

 meantime watching the plate through the coloured glass ; the 

 washing is then pioceeded with in the same manner.— Dr. Stem 

 proposes to use this method for photographing the transit of 

 Venus.— Prof. Schmidt contributes a paper on the rotation 

 of Jupiter, in which he discusses all the old observations of 

 Cassini and others. From his list we gain that these observers 

 differed to the amount of 6™, the minimum being f)'^ 50"^, and the 

 maximum gl" 56">. From Prof. Schmidt's observations in 1873, 

 he obtains a period of g'' 56"" 7'2% 



Archives des Sciences Physiqtus et Naturelles, Dec. 15, 1873.— 

 In this number a short opening notice of M. de la Rive is fol- 

 lowed by an article by M. Wiedemann, being an extract from 

 his recent work on elliptic polarisation of light, and its relations 

 with the superficial colours of bodies. The author shows that 

 superficial colours change considerably with the nature (indices 

 of refraction) of the substances in contact with which they are 

 produced ; and colours the most strongly reflected present gene- 

 rally the most intense elliptic polarisation, provided the reflec- 

 tion occurs in air or in vacuo. The principal angles of incidence 

 undergo the most rapid modifications for wave-lengths corre- 

 spondinij nearly to the bands of absorption. M. Wiedemann's 

 work elucidates the connection between the phenomena of bodies 

 with superficial colours and the principal angles of incidence and 

 relations of amplitude.— Dr. Hermann Miiller's recent interest- 

 ing work on fertilisation of flowers by insects is reviewed m a 

 paper which gives a succinct ii'sume of the principal results. — 

 M. Plantamour furnishes an account of the proceedings of the 

 Meteorological Congress held at Vienna in 1S73, and the circum- 

 <;tances which lei to" it. — There is also a note on the early deve- 

 lopment of Geryonides, by M. Fol ; and this is followed by the 

 usual scientific summary. 



Ocean Highways, February.— About one-third of this number 

 is occupied by a paper by Captain R. F. Burton, describing 

 "Two Trips on the Gold Crast," the first being to the Beauhh 

 Gardens snd Agrimanti Hiils, and the second along the shore to 

 the Volta River. The paper, which is written in Captain Bur- 

 ton's characteristic and attractive style, and illustrated by 

 two maps, is full of information, and will no doubt prove in- 

 teresting to many at the present time. An article on the Bengal 

 Famine recounts the principal Indian famines from 1661 to the 

 present time, and shows how much could be done to foresee and 

 obviate the consequences of famine by a more scientific investi- 

 gation of the laws which regulate meteorological phenomena. 

 The article is accompanied by a map showing the extent of the 

 famine districts. In a short aiticle on " Wyche's Land," called 

 by the f Sermans after King Karl of Wurtemburg, it is shown 

 satislactorily, we think, that the honour of the discovery, by 

 rioht, belongs to Edge's expedition in 161 7, and that the name 

 t)u:n ' imposed should remain unchanged. Some interesting 

 details are given of Richard Wyche or Wiche, the London mer- 

 chant, who did much to encourage early discovery. Other 

 articles are on " Kuropean Emigration to the Argentine Re- 

 public," and on the " Piovindah Trade," or trade of the Lohani 

 merchants, who are the channels of communication between 

 India and Central Asia. 



SOCIETIES AND ACADEMIES 



Royal Society, Feb. 12.—" On the Division of Sound by a 



layer of flame or heated gas, into a reflected and a transmitted 



portion," by John Cottrell, Assistant in the Physical Laboratory 



of the ' Royal Institution ; communicated by Prof. Tyndall, 



"Avibr.ating bell contained in a padded box was directed so as 

 to propagate a sound-wave through a tin tube and its action ren- 

 dered manifest by its causing a sensitive flame placed at a dis- 

 tance in the direction of the sound-wave to become violently 

 agitated. , , . 



The invisible heated layer immediately above the lummous 



portion of an ignited coal-gas flame issuing from an ordinary 

 bat's-wing burner was allowed to stream upwards across the end 

 of the tin tube, from which the sound-wave issues. A portion 

 of the sound-wave, issuing from the latter, was reflected at the 

 limiting surfaces of the heated layer ; and a part being trans- 

 mitted through it, was now only competent to slightly agitate the 

 sensitive flame. 



The heated layer was then placed at such an angle that the 

 reflected portion of the sound-wave was sent through a second 

 tin tube (of the same dimensions as the above), and its action 

 rendered visible by its causing a second sensitive flame placed at 

 the end of the tube to become violently affected. This action 

 continued so long as the heated layer intervened ; but upon its 

 v/ithdrawal the first-mentioned sensitive flame, receiving the 

 whole of the direct pulse, became again violently agitated, and 

 at the same moment the second sensitive flame, ceasing to be 

 affected, resumed its former tranquillity. 



Feb. 19.— " On the Number of Figures in the Period of the 

 Reciprocal of every Prime Number below 17,000," by William 

 Shanks, Houghton-le-Spring, Durham. 



"On an Instrument for the Composition of the Harmonic 

 Curves," by E. A. Donkin, Fellow of Exeter College, Oxford. 



"On the Absorption of Carbonic Acid by Saline Solutions," 

 by J. Y. Buchanan, chemist on board H.M.S. C/ialleii^er. 



Linnean Society, Feb. 19. — J. Gwyn Jeffreys in the chair. 

 — The chairman announced that a .Special General Meeting of 

 the Society would be held on Thursday, March 5, at 8 P.M., to 

 consider alterations in the Bye-laws of the Society." The 

 following papers were read : — Systematic list of the Spiders at 

 present known to inhabit Great Britain and Ireland, by the Rev. 

 O. P. Cambridge. — Some observations on the vegetable produc- 

 tions and rural economy of the province of Baghdad, by Surgeon- 

 major W. H. Colvill. — Note on the Bracts of Crucifers, by Dr. 

 M. T. Masters. 



Zoological Society, Feb. 17.— George Busk, F.R.S. vice- 

 president, in the chair. Mr. Busk exhibited some skulls of the 

 tiger and leopard from China, procured by Mr. R. Swinhoe, 

 and showed that those from the northern and southern pro- 

 vinces did not appear to be specifically distinct. — A communica- 

 tion was read fiom Mr. L. Taczanow.ski, Conservator of the 

 Museum of Warsaw, containing the descriptions of twenty-four 

 new birds, obtained by Mr. Constantine Jelski in Central Peru. 

 Amongst these was a new Cotingine form, proposed to be 

 called Dolyornis sclaleri, and four new humming-birds named 

 respectively ISIetallura hedvi^cc, Helianthea dichroura, Erio- 

 cncmis sapphiropygia and Lainpraster branickii. — A ^ ommunica- 

 tion was read from Sir Victor Brouke, Bart., describing a new 

 species of Gazelle, founded on two specimens living in the 

 Society's Menagerie, which he proposed to call Ga%eUa mnsca- 

 tensis. — A communication was read from Dr. T. Schomburgh, 

 Director of the Botanic Gardens, Adelaide, containing an account 

 of the habits of the Australian Coote (Fiilica australis) as ob- 

 served in the Gardens under his charge. — Mr. E. Ward ex- ' 

 hibited the head of a supposed new species of Wild Sheep, 

 from Ladak, which he proposed to name Ovis brookei, after .Sir 

 Victor Brooke. — Dr. J. E. Gray, F.R.S. , communicated some 

 notes on the Crocodile of Madagascar, which he proposed to 

 distinguish from Crocodilus vulgaris of Continental Africa, and 

 to call Crocodilus madagascaricnsis. — A communication was read 

 from Mr. W. N. Lockington, of Humboldt County, California, 

 conLiining some notes on the mammals and birds met with in 

 that part of the State of California. 



Mathematical Society, Feb. 12.— Dr. Hirst, F.R.S., 

 president, in the chair. — Piof. Clifford gave in some detail a 

 statement of the views advanced in his paper on the foundations 

 of djnamics. — A discussion ensued, in which Messrs. Wilkinson, 

 Moulton, Cayley, Roberts, and G. H. Lewes took part. — Mr. 

 Clifford having answered questions .and replied to tlijections, 

 proceeded next to give an account of a paper on the frte motion 

 of a .solid in elliptic space. — Owing to the lateness of the hour a 

 paper by Mr. C. J. Monro, entitled "Note on the Invirslon of 

 Bernoulli's Theorem in Probabilities," was taken as read. Under 

 the name of Bernoulli's Theorem are comprehended two 

 theort mi which, with a little licence, we may distinguish as the 

 deductive and tlie inductive. The deductive theorem assumes 

 the constant proliability/ of a given result on a single trial, and 

 determines the probability P that on m trials the result wijl be 

 produced from mp —/to mp + / times, or from x — / to .r + /, 

 if .1 is the greatest integer in mp -|- /. The inductive theorem 



