298 



NATURE 



\Feb. lo, 1876 



SOCIETIES AND ACADEMIES 



London 



Royal Society, Jan, 20. — Certain cases of electromotive 

 force sustained by the action of electrolytes on electrolytes, by J. 

 Hopkinson. Communicated by Sir VV. Thomson. 



On reversed photographs of the solar spectrum beyond the 

 red, obtained on a collodion plate, in a letter to Prof. Stokes, 

 by Capt. J. Waterhouse, Assistant Surveyor- General of India. 

 Communicated by Prof. Stokes. 



Jan. 27. — Contributions to the minute anatomy of the thyroid 

 gland of the dog, by E. Cresswell Barer, M.D., Lond. Com- 

 municated by Dr. Klein, F.R.S. 



Results of the monthly observations of magnetic dip, horizontal 

 force, and declination made at the Kew Observatory, from April 

 1869 to March 1875 inclusive, by the Kew Committee. 



Researches on the minute anatomy of the alimentary canal, by 

 HerbertWatney,M. A., Demonstrator of Microscopical Anatomy 

 at St. George's Hospital. Communicated by Dr. Klein, 

 F.R.S., Assistant Professor in the Brown Institution. 



Linnean Society, Jan. 20. — Prof. G. J. Allman, F.R.S., 

 president, in the chair. — Prof. Oliver communicated a short 

 paper, by Prof. H. G. Reichenbach, being the twenty-ninth 

 contribution to the botany of the Challenger, viz., On some 

 Orchidaceaj collected by Mr. Moseley of the Challenger expedi- 

 tion, in the Admiralty Islands, Ternate, and Cape York — one 

 of which forms the type of a new section of the genus Dendro- 

 bium. — The Fungi of Brazil, by the Rev. M. J. Berkeley and Dr. 

 M. C. Cooke. The authors include the collection made by Mr. 

 J. H. Trail in 1874, and state that all the Brazilian fungi yet 

 known amount to but 437 species. Among these there are of 

 Hymenomycetes, 356 ; Gasteromycetes, 13 ; Hyphomycetes, 7 ; 

 Coniomycetes, 5 ; Ascomycetes, 55 ; incomplete, i — total, 437. 

 About 300 of these are confined to Brazil, the remainder found 

 in other parts of the world. The great Brazilian region, there- 

 fore, with but 437 representatives, contrasts with 886 enumerated 

 for Cuba, and 1,190 for Ceylon. This paucity of species in the 

 first-mentioned area, the authors suggest, may be due to incom- 

 pleteness of collection, or presumably as yet deficient knowledge 

 of microscopical forms. — On a new species of oak from the 

 Sikkim Himalaya, by Dr. George King, F.L.S., Supt., Roy. 

 Bot. Gard., Calcutta. This, the Quercus Andersoni, or 

 "Katoos"of the Nepaulese, is one of the finest forest trees, 

 and largely used by the European residents of Darjeeling. It 

 occurs at higher altitudes than Q. spicata, and in other respects 

 differs. — On Steere's sponge, a new genus of the Hexactinellid 

 order of the Spongidas, by Dr. James Murie. Obtained in deep 

 water between the islands of Negros and Zebu, the present adds 

 one more rarity to the already remarkable sponge fauna of the 

 Philippines. The siliceous skeleton of Dendrospongia steereii 

 bears resemblance to a branching coral or shrub, and is nearly 

 three feet high. A peculiar rosette-like series of tufts form a 

 continuous whorl, winding spirally up the branches. Micro- 

 scopical examination shows the spicules to belong to the sex- 

 radiate type : the character of these, with the presence of a veil 

 and other structural points, indicate its being an intermediate 

 type between such forms as Dactylocalyx, Aphrocallistes, Hoi- 

 tenia, and Meyerina. The homology of the so-called root, body, 

 and beard spicules of several of the siliceous sponges being noted, 

 those of Dendrospongia are compared ; the spiral tufts of the 

 latter agreeing in many respects with the spicular fringes of 

 Euplectella, &c. 



Chemical Society, Feb. 3. — Prof. Abel, F.R.S., president, 

 in the chair. — Mr. W. Ackroyd read a paper on metachromism, 

 or colour change. Metachromism, from the Greek ix^to., change, 

 and xP'^i"«» colour, is the term applied to the phenomenon inves- 

 tigated, viz., the change in colour observed in bodies when 

 heated at comparatively low temperatures. For convenience 

 sake colour-changing bodies were called metachromes. No 

 mention is made of the subject in text-books, and only here and 

 there in scattered memoirs. The views of Stahl, Delaval, 

 Brewster, Schoenbein, Gladstone, and Houston and Thomson 

 were spoken of and discussed. Colour change takes place in the 

 order of the spectru7n colours : when a metachrome is expanding, 

 in the violet to red order ; "when contracting, red to violet order. 

 Such colour change it was pointed out might be taken as an 

 indication of expansion or contraction, the anomalously behaving 

 body Agl fully bearing out the author's conclusions. Meta- 

 chromes were divided into two classes : (i) the zinc oxide class ; 

 and (2) the borate of copper class. From a study of the two 



classes the following metachromatic scale was arrived at : white, 

 colourless, violet, indigo, blue, green, yellow, orange, red, brown, 

 black — metallic appearance. The colours of the more refrangible 

 end may be replaced by a metallic appearance. Metachromism 

 has an important bearing on allotropy. A body expanding 

 through the influence of heat being really a continuous series of 

 allotropes. In support of this the relation of colour and density 

 was discussed. It was shown that metachromism is due to the 

 storage of potential energy, the author holding that molecular 

 vibrations or kinetic energy have nothing to do with this pheno- 

 menon of selective absorption. Contracting metachremes chang- 

 ing from less to more refrangible colours, where would this 

 change cease providing a long enough temperature could be 

 had ? Presumably at the absolute zero of temperature, and at 

 this point all metachromes would be white or metallic-looking, 

 judging from their behaviour at attainable temperatures. Fol- 

 lowing expanding metachromes from this absolute zero of colour, 

 the change in each would vary with the coefficient of expansion, 

 giving us at the normal temperature all that diversity of hue 

 which characterises the inorganic world. Including certain cases 

 of decomposition (given in table) colour change may denote ( i ) 

 If to more refrangible, o contraction or /3 decomposition ; (2) If 

 to less refrangible, o expansion or ^ combination. The obser- 

 vations relate to anhydrous and for the most part binary com- 

 pounds. — Mr. W. H. Perkin, F.R.S., made a communication 

 on the formation of anthra-purpurin, which it appears is the 

 product of t.he action of caustic alkali on anthraquinone-disul- 

 phoric acid. The supposition that alizarin is formed under 

 these circumstances being incorrect. — There were also paper* on 

 mattose, by Mr. C. O. Sullivan ; on a simple form of gas regu- 

 lator, by Mr. J. Fletcher ; and on high melting points, with special 

 reference to those of metallic salts, by Mr. T. Camelley, B.Sc. 



Zoological Society, Feb. i.— Mr. G. R. Waterhouse, vice- 

 president, in the chair. — The Secretary read some extracts from 

 a report of a recent visit made by H.M.S. Petrel to the Gala- 

 pagos Islands, communicated by the First Lord of the Admiralty, 

 and refer: ing to the tortoises met with in the different islands of 

 the group. — Mr. Sclater exhibited and made remarks on an 

 antler of a Rusa Deer, living in the Gardens of the Acclima- 

 tisation Society of Melbourne, which had been sent to him for 

 identification. — Mr. Frederick Selous, jun., exhibited and made 

 remarks on a series of horns of African Rhinoceroses procured 

 by himself in South-eastern Africa. — Prof. T. H. Huxley, 

 F. R.S., read a paper on the position of the anterior nasal aper- 

 ture in Lepidosiren, which he showed to be strictly homologous 

 with the position of these organs in other vertebrates. — Mr. A. 

 H. Garrod read a paper on the anatomy of Chauna derbiatia, 

 and on the systematic position of the Screamers [Palamedeida:), 

 in which he controverted Prof. Parker's collocation of this form 

 with the Anseres, and showed that it should occupy an indepen- 

 dent position with relations to the Struthiones, Gallinae, and 

 Rallidse. — A communication was read from Mr. F. Jeffrey Bel), 

 containing notes on the myology of the limbs of Moschus mos- 

 chiferus. — A communication was read from Dr. T. Spencer 

 Cobbold on Entozoa, forming the third of a series of papers on 

 this subject brought by him before the Society. — Mr. Herbert 

 Druce read a list of butterflies collected in Peru, with descrip- 

 tions of new species. To these were added some notes on some 

 of the species, by Mr. Edward Bartlett. — Mr. A. G. Butler read 

 some notes on a small collection of butterflies received from the 

 New Hebrides. — A paper by Mr. P. L. Sclater and Mr. O. 

 Salvin was read, in which they gave descriptions of some new 

 burds obtained by Mr. C. Buckley, in Bolivia. 



Physical Society, Jan. 29. — The president, Prof. Gladstone, 

 F.R.S., in the chair. — The following candidates were elected 

 members of the Society: — Sir John Conroy, Bart., and H. S. 

 Burls. — The Secretary then read a communication from Mr. J. A. 

 Fleming on the polarisation of electrodes in water free from air. 

 The experiments described were undertaken in order to meet 

 objections which had been raised by Prof. Rowland to a previous 

 paper by the author, in which he endeavoured to show that 

 when an electrolyte flows in a very strong magnetic field the 

 electromotive force generated by its motion effects the electro- 

 lysis of the liquid, a fact which he holds to be proved by the 

 subsequent polarisation of the electrodes. Prof. Rowland con- 

 sidered that the effect observed was due to the presence of 

 dissolved air, and conversely, that in air-free water, at any rate 

 with the same electromotive force, similar effects would not be 

 observed. These'doubts raise the two questions ( i ) in air-free water 

 can platinum electrodes be polarised by a very small electromotive 



