I40 



NATURE 



{Dec. 12, 1 8; 8 



and classification of the finer grades of purity or impurity. The 

 errors incidental to the process form an array of difficulties 

 which become infinitely serious, seeing that the range (as regards 

 albumenoid ammonia) between pure and dirty waters is com- 

 paratively small. The combustion process has all the evils of 

 evaporation to encounter, but the organic carbon estimation is 

 trustworthy ; the organic nitrogen determination, however, 

 scarcely yields absolutely trustworthy evidence on which to 

 found an opinion as to the probable source of the organic matter. 

 The process, nevertheless, is of great value. The oxygen (per- 

 manganate) process avoids the errors incidental to evaporation ; 

 its results (when properly used) are constant and extremely deli- 

 cate ; it draws a sharp line between the putrescent or probably 

 pernicious and the non-putrescent or probably harmless organic 

 matter ; by it a bad water can never be passed as good. As far 

 as the three processes are concerned, the oxygen and combustion 

 processes give closely concordant results, whilst those yielded by 

 the ammonia process are often at direct variance with both. 



Photographic Society, November 12. — James Glashier, 

 F.R.S., in the chair. — After the medals awarded for the best 

 pictures in the exhibition had taken place, a paper by Leon 

 Warnerke was read — photogi-apbic notes from a travel in Russia 

 with exhibition of various works, apparatus, and materials. 

 John Thomson, F.R.G.S., described his photogi-aphic 

 experiences in Cyprus. Mr. Warnerke described the artistic 

 and scientific progress of photography in Russia as having arrived 

 at a high state of perfection, as also the very important position 

 which photo-lithography occupies in the Government establish- 

 ments of the country where large_;maps of the Russian frontiers 

 are produced. 



Boston, U.S.A. 



American Academy of Arts and Sciences, November 13. 

 — Hon. Charles Francis Adams in the chair. — Prof. Mitchell, 

 of the U.S. Coast Survey, read a monograph upon the tides of 

 the Gulf of Maine. The results of the late surveys prove that a 

 lift of the tide far out from shore requires an almost inappreciable 

 time to be felt along the coast. The variations in the tides were 

 shown to come from the north rather than from the south. In 

 the discussion of Prof. Mitchell's paper Prof. Benjamin Peirce 

 maintained that the results corroborated his own theory of vibra- 

 tions and nodal points. — Prof. A, E. Dolbear, of Tuft's College, 

 read a paper upon his claims of the invention of the speaking- 

 telephone, and exhibited his early models and also a great 

 variety of new speaking-telephones. Among these were a 

 Morse sounder transformed into a telephone ; a miniature voltaic 

 cell, one plate of which was spoken against, and speech thus 

 transmitted ; an electrophone depending upon the variable resist- 

 ance of the extra spark, which can transmit speech over a dis- 

 tance of more than two hundred miles ; various forms of trans- 

 mitters and modifications of Reiz's telephone, which Prof. 

 Dolbear said are innumerable. — Mr. N. D. C. Hodges exhibited 

 a new instrument for determining the^ magnetic dip. Two soft 

 iron bars joined at right angles move on a vertical graduated 

 circle. A small magnet with a mirror is suspended at the point 

 of crossing of the pieces of soft iron. ^Vhen the latter make 

 equal angles with the line of dip, the magnet remains at zero. 

 By four simple reversals and measurements the residual magnetism 

 of the iron is eliminated. The instrument gives very constant 

 results and requires less 'time to make an observation than the 

 ordinary dipping needle. 



Paris 



Academy of Sciences, December 2.— M. Fizeau in the 

 chair. — The following papers were read :— On the torsion of 

 prisms of mixtilinear base, and on a peculiarity which may be 

 presented by certain uses of the logarithmic co-ordinate of the 

 isothermal cylindrical system of Lame, by M. De Saint Venant. 

 — M. Marey was elected Member for the section of Medicine and 

 Surgery in the room of the late M. CI. Bernard, the other can- 

 didates being MM. Bert, Charcot, and Gubler. — Experimental 

 researches on meteoritic nickelised irons ; mode of formation of 

 concretionated syssidera, by M. Meunier. The mixtiu-e of 

 chlorides of iron and nickel gives, by reduction in hydrogen, 

 alloys perfectly definite, and sometimes beautifully crystallised. 

 Association of the alloys together can be effected in two ways 

 (specified). Next, grains of peridot or fragments of dunite can 

 easily be covered with a continuous coat of various alloys of iron 

 and nickel, the metallic concretion sometimes penetrating into 

 the fine fissures of the stone. By placing the pieces of rock 

 repeatedly in the incrusting medium fed with diverse mix- 



tures of the itwo' chlorides, superposed deposits of various 

 alloys are obtained, and a complete facsimile of the cosmic 

 rocks in question.— On a new phenomenon of static electricity, by 

 M. Govi. A reference to his former experiments on the pheno- ■ 

 menon studied by M. Duter. Different liquids having given 

 different amounts of contraction, and mercury no contraction, he 

 inferred condensation of the liquid against the walls of the jar. 

 He apparently doubts M. Duter's conclusion. — On the electro- 

 motive force of induction arising from rotation of the sun ; deter- 

 mination of its amount and direction, whatever the distance of 

 the induced body, by M. Quet. He gives a mathematical esti- 

 mate of the force, with formulae. — Note on the efifects of vapours 

 of sulphide of carbon, by M. Poincare. He experimented on 

 animals, with reference to the symptoms presented by workmen 

 in vulcanisation of caoutchouc. Guinea pigs and frogs resist the 

 action much less than man ; and the period of excitation is 

 wanting in them, the manifestations being mainly paralytic. 

 The auricles are distended with dark blood, livid spots appear 

 in the lungs, the brain is often reduced to a diffluent pulp, and 

 drops apparently of sulphide of carbon form in the cerebral 

 vessels, blocking the passage of blood corpuscles and some- 

 times causing rupture. The author considers the use of 

 vulcanised caoutchouc should be restricted to really useful 

 objects, and that the manufacture of small balloons and toys 

 of it should be interdicted. — On the mode of formation of 

 some phylloxeric nodosities, by M. d'Arbaumont. — Latitude of 

 Algiers, and fundamental azimuth of the Algerian triangulation, 

 by M. Perrier. The author describes his method. — Nebulce 

 discovered and observed at the Observatory of Marseilles, by 

 M. Stephan. — Double stars ; certain groups of perspective, by 

 M. Flammarion. — Evaluation of a definite integral, by M. 

 Appell. — On the repulsion resulting from radiation, by Mr. 

 Crookes. — Note on cholalic acid, by M. Destrem. — Researches 

 on vaso-motor nerves, by MM. Dastre and Morat. The prin- 

 cipal branch of termination of (he sciatic nerve plays, with regard 

 to the region of the finger, the rolt of a vaso-constrictor nerve, 

 and there is no ground for supposing, in this nerve-trunk, vaso- 

 dilator nerves either more or less than in the cervical cord of the 

 sympathetic. Thus the controverted point as to whether the 

 sciatic is a vaso-dilator nerve, is answered in the negative. The 

 authors generalise the results, applying them to the nervous 

 trunks which go to the skin. — Onthe cardiac and respiratory effects 

 of irritations of certain sensitive nerves of the heart, and on the 

 cardiac effects produced by irritation of sensitive nerves of the. 

 respiratory apparatus, by M. Fran9ois-Franck. Different effects 

 are produced according as an irritating injection (say hydrate of 

 chloral) is made into the right or the left heart ; in the former 

 case there is diastolic stoppage of^the heart, in the latter systolic 

 (The mechanism of these effects is studied.) — On the change of 

 form of fixed cells of loose connective tissue in artificial cedema, 

 by M. Renaut. 



CONTENTS Page 



Lord Raylhigh's Theory of Sound. By Prof. H. Helmholtz, 



F.RS 117 



Our Book Shelf:— 



Cams' " Zoologischer Anzeiger " iiS 



Lorentz's " Vegetacion del Nordeste de la Provinciade Entre-Rios. 



Informe Cientifico " . 119 



Letters TO THE Editor:— ' 



Was Homer Colour-BImd?—R. C.f A. Prior 119 



Colour-Blindness. — Dr. William Pole 120 



The Colour Sense. — Dr. Ernst Krausk . . 120 



History of the Speaking Telephone. — Prof. W. F. Barrett . . izi 

 The Formation of Mountains. — Alfred R. Wallace ; Arthuu 



Ransom 121 



New Galvanometer for Strong Currents. — John Trowbridge . . 121 



Explanatory. — Richard A. Proctor . . . . ^ 121 



Graphic Granite. — Frank Johnson 122 



The Phonograph and Vowel Sounds. — Dr. F. Auerbach . . . 122 



Local Colour- Variation in Lizards. — P. Herbert Carpenter . . 122 



The Range of the Mammoth. — Clement Reid 122 



The Bunsen Flame a Sensitive Flame. — W. W. Haldare Gee . 122 



Our Astronomical Column :— 



Jean Dominique Cassini • i2« 



The Second Comet of 1582 .... . 123 



GEOaRAPNICAL NoTES I23 



Are the Fossil Floras of the Arctic Regions Eocene or 

 Miocene ? and on the Cause> which enabled them to exist 



IN High Latitudes. By J. Starkie Gardner 124 



On Gaussin's Warning Regarding the Sluggishness of Ship's 



Magnetism. By Sir Wm. Thomson, F.R.S. (With lUustratimi) . 127 



Mathematical Drawing Instruments {JVith Illitstrations) . . . 12S 



Notes 130 



Royal Society — The President's Anniversary Address, II. By 



Sir Joseph Hooker, K.C.S.I., C.B., F.R.S 132 



Haeckel on THB Libsrty of Science AND of Teaching, II. . . . 135 



University and Educational Intelligence '37 



Societies and Academies i37 



