December 9, 1807 



NA TURE 



M3 



sions by Archimedes," and communicated a paper by M. 

 Lemeray, entitled " Quatrieme Algorithme Nature!." The 

 following were elected office-bearers for the current session : — 

 President, Mr. J, B. Clark ; Vice-President, Dr. Alexander 

 Morgan ; Hon. Secretary, Mr. J. W. Butters ; Hon. Treasurer, 

 Mr. D. Tweedie ; Editors of Proceedings, Mr. W. J. Mac- 

 donald, Dr. Knott, Mr. Charles Tweedie ; Committee, Messrs. 

 G. Duthie, R. F. Muirhead, and J. D. H. Dickson. 



Manchester. 

 Literary and Philosophical Society, November 30. — 

 Mr. J. Cosmo Melvill, President, in the chair. — Mr. H. W. 

 Freston (Prestwich) and Mr. C. E. Stromeyer (Manchester) 

 were elected ordinary members of the Society.— The President 

 announced that the Council had awarded the Wilde Gold Medal 

 of the Society for 1898 to Sir Joseph Dalton Hooker, C.B. , 

 K.C.S. I., F. R.S., in recognition of his eminent services to all 

 branches of botanical science ; and had awarded the Dalton 

 Medal of the Society (struck in 1864) for 1898 to Dr. Edward 

 Schunck, F. R. S. , for his remarkable series of researches on the 

 natural colouring matters ; also, that the premium for 1898 of 

 fifteen guineas had been awarded to Mr. John Butterworth, of 

 Shaw, for his paper, printed in the Alanchester Memoirs, on 

 some further investigations of fossil seeds of the genus Lageno- 

 sforna (Williamson). — Prof. H. Lamb read a paper entitled 

 " On waves in a medium having a periodic discontinuity of 

 structure." The main object of the paper is to examine the 

 selective total reflection which takes place at the boundary of 

 a medium of this character. In the examples chosen for dis- 

 cussion the medium is represented by a string supposed to be 

 capable of longitudinal vibrations, and the periodic interruption 

 of properties may consist in a series of attached masses, or of at- 

 tached particleS; which are, moreover, urged towards fixed posi- 

 tions by springs, or to particles connected with the string by loose 

 springs. The same analysis applies to media constituted in 

 many other ways, and it is further shown how the methods may 

 be adapted to cases where dynamical systems of a much more 

 general character are interpolated at regular intervals. There 

 are some instructive contrasts between the results obtained in 

 the special cases above enumerated ; in particular, in the last- 

 mentioned case (that of particles attached by loose springs) it 

 appears that relatively short waves may be transmitted freely 

 unless the wave-length happens to fall within certain narrowly 

 defined intervals. We have here, perhaps, an illustration of 

 the theory of refraction sketched by Sir George Stokes in the 

 Wilde Lecture ; but some caution is, of course, necessary in 

 drawing inferences as to theories of radiation and absorption 

 from the study of a one-dimensional model. 



Paris. 



Academy of Sciences, November 29. — M. A. Chatin in 

 the chair. — New method of preparing carbides by the action of 

 calcium carbide upon oxides, by M. Henri Moissan. Calcium 

 carbide reacts with many metallic oxides at the temperature of 

 the electric furnace, giving the carbide of the metal and lime, 

 the latter being again partially converted into carbide by the 

 carbon of the crucible. The carbides of aluminium, manganese, 

 chromium, molybdenum, tungsten, titanium, and silicon were 

 obtained by this method. The oxides of lead, bismuth' and tin 

 gave the pure metals on similar treatment. — Experimental 

 typhoid infection, produced by the introduction of a virulent 

 culture into a Thiry cavity, by MM. R. Lepineand B. Lyonnet. 

 — M. Ditte was elected a Member in the Section of Chemistry, 

 in the place of the late M. Schiitzenberger. — Report on a 

 memoir of M. Le Roy, entitled "On the integration of the 

 equations of heat." — Observations of the new planet Villiger 

 (1897, November 19) made at the Observatory of Algiers, by 

 MM. Rambaud and Sy. — On two occultations of the Pleiads 

 by the moon, by M. Lagrula. The observations are utilised 

 for the determination of the semi diameter and parallax of 

 ' the moon at its mean distance. — Employment of the method 

 of least squares to reveaF the presence of systematic errors, by 

 M. Jean Mascart. The determination of the vertical by means 

 of the meridian circle is subject to errors much larger than would 

 follow from the possible error of each microscope reading. 

 With a view to see how far these fluctuations were due to 

 alterations of temperature, a series of fifty determinations was 

 made, giving fifty equations of condition for each microscope for 

 three unknowns, the deviations being assumed as a quadratic 

 function of the temperature. The results showed, however, 



NO. 1467. VOL. 57] 



that the fluctuations due to temperature changes are extremely 

 small, and that the comparatively large errors observed must be 

 due to other causes — Observations of the sun made at the 

 Observatory of Lyons, with the Brunner equatorial, 

 during the third quarter of 1897, by M. J. Guil- 

 laume. — Influence of altitude and of heat upon the 

 decomposition of oxalic acid by sunlight, by M. J. 

 Vallot and Mme. Gabrielle Vallot. It has been found 

 that, although oxalic acid is practically undecomposed by heat 

 alone, the velocity of the reaction with actinic light is very 

 greatly accelerated by a rise of temperature. Thus two solu- 

 tions of oxalic acid exposed to sunlight under similar conditions, 

 except that one was maintained 12° higher than the other, gave 

 decompositions of 10 and 50 per cent, respectively. The rate 

 of decomposition also increased rapidly with the altitude. — On 

 the fundamental theorem of projective geometry, by M. H. G. 

 Zeuthen. — On the equation to periods, by M. X. Stouff. — On 

 the Bessel functions S"(a-) and 0"{x), by M. L. Crelier. — On 

 the statical and dynamical explosive potentials, by M. R. 

 Swyngedauw. A reply to some criticisms of M. Jaumann. — A 

 simple method of proving the change of period of sodium light 

 in a magnetic field, by M. A. Cotton A flame feebly tinged 

 with sodium is observed through another flame also containing 

 sodium. The edges of the second flame appear to be black, 

 owing to its gaseous envelope being absorbent. Any small 

 change in the period of vibration of the more distant flame, pro- 

 duced by the action of the magnetic field, suppresses the absorp- 

 tion, and causes the black border of the interposed flame to dis- 

 appear. In this way it is easily shown that a change of period 

 of light emitted parallel to the lines of force, completely ex- 

 tinguishes the dark border, whilst with observations made per- 

 pendicularly to the lines of force, the border grows lighter on 

 completing the circuit round the magnet, but does not com- 

 pletely disappear. — Osmotic researches on very dilute solutions 

 of cane sugar, by M. Ponsot. The author was successful in 

 making membranes impermeable to sugar. With these measure- 

 ments of osmotic pressure were made of sugar solutions con- 

 taining only i '235 and o"6i75 grams per litre. The mean of 

 the observed pressures was exactly equal to that calculated by 

 the Van t' Hoff formula, on the assumption that no dissociation 

 of the sugar took place, or the coefficient i = i. — On the 

 alcoholic isocyanurates and the constitutional formula of cyan- 

 uric acid, by M. Paul Lemoult. The heats of combustion of 

 methyl and ethyl isocyanurates were determined, and the 

 conclusion drawn that isocyanuric acid has a ring-shaped con- 

 stitution, a symmetrical tricarbimide, — Quinones and hydro- 

 quinones, by M. Amand Valeur. Determinations of the 

 heats of combustion of toluquinone, thymoquinone, hydro- 

 quinone, hydrotoluquinone, and hydrothymoquinone. — On 

 the transformation of sorbite into sorbose by the Mycoderma 

 villi, by M. A. Matrot. The best experimental conditions for 

 the production of sorbose from sorbite by means of the yeast 

 Mycoderfiia vim are worked out in detail. — On the germinative 

 plates of the Coleoptera, by M. A. Lecaillon. For certain 

 Coleoptera it is shown that the blastula stage does not appear in 

 development, the gastrula stage following immediately upon 

 segmentation, and showing no typical invagination. — On the 

 Rouget, a human parasite, by M. Brucker. This parasite, which 

 appears as a parasite to man in August and September, is shown 

 to be probably the larva of Tro?nbidium gymnopterortim. — On 

 the culture of the nostoch in presence of glucose, by M. Raoul 

 Bouilhac— On the characteristics of nerve and muscle stimula- 

 tion, by M. G. Weiss. A reply to the criticisms of M. Dubois. 

 The author claims that the experiments cited by M. Dubois 

 are in reality confirmatory of his views. — Analysis of vocal 

 sounds by the phonograph, by MM. Marichelle and Hemardin- 

 quer. In spite of the various influences which act upon the form 

 of the period, such as musical pitch, intonation, intensity, and 

 individual conformation of the sounding organ, each vowel is 

 distinguished by certain invariable characters, constituting it a 

 real individual. — On the absorption of organic materials by roots, 

 by M. Jules Laurent. Experiments were made with maize upon 

 solutions of glucose and invert sugar, and in every case a certain 

 quantity of the sugar was absorbed by the roots, the amount of 

 which appeared to be proportional to the dry weight of the plant. 

 The sugars are utilised by the plant, and in great part excreted 

 as carbon dioxide. — The favourable times in the treatment of 

 black rot, by M. A. Prunet. A treatment with copper salts ap- 

 plied immediately after one invasion of the disease, acts bene- 

 ficially against a future invasion, the maximum effect being pro- 



