March 8, 1900] 



NATURE 



459 



K 



C. Dixon. The results include those of Hamburger's paper 

 relics Jotitfta/, vol. xciii.), but are somewhat wider in 

 application and point to a further generalisation. — On the cal- 

 culation of the double integral expressing normal correlation, 

 W. F. Sheppard. When the measures of two organs vary about 

 their mean value according to the normal law, and the 

 statistical correlation of the two sets of variations is also 

 normal, the frequency of joint variation within any selected 

 imits is expressed by the integral considered in the paper. 

 — On the hemihedrism and twinning of crystals of Dolo- 

 mite from the Binnenthal, R. H. Solly. Mr. Solly ex- 

 hibited a number of crystals with diagrams and models to 

 explain the hemihedrism and twinning. Some new forms 

 were notified. — Apparatus for measuring the extension of 

 wires, G. F. C. Searle. Two wires A, B are hung side by 

 side from the same support ; the apparatus is designed to 

 measure the extension of B relative to A, which is treated as 

 a standard. To the lower ends of A and B are attached the 

 upper ends of two brass frames C, Z>, and from the lower ends 

 of these frames there hang respectively a constant weight and a 

 scale pan. The two frames are kept parallel by a pair of links 

 so arranged that the frames are capable of small relative 

 vertical displacements. To the frame C is pivoted one end of a 

 spirit level, of which the other end rests upon the end of a 

 screw working in a nut fixed to D. When a load is placed in 

 the pan hanging from Z?, the wire B is stretched and the bubble 

 of the level is displaced. To bring the bubble back to its zero 

 position the screw must be advanced through a distance which 

 is exactly equal to the extension of the wire B. In this manner 

 an extension of i/iooo millimetre can be detected. With 

 copper wire it is possible to detect hysteresis when the 

 maximum extension is only i/ioo per cent, of the total length. 

 — Magnetic disturbances in the Isle of Skye, Alfred Harker. 

 It has long been known to climbers that in the Cuillin Hills 

 the compass often becomes useless as a guide. On examination 

 it is found that the most violent disturbances are localised at 

 the summits and salient points on the ridges, and are due to 

 intense permanent magnetisation with a curiously irregular dis- 

 tribution in the mass of the rock. This is ascribed to atmo- 

 spheric electricity. It is found not only in the Cuillins, but 

 equally on the moorland hills which make up all the north- 

 western half of Skye ; the gabbro of the former tract and the 

 basalt of the latter are both rocks rich in iron. It is next shown 

 that areas sometimes hundreds of yards in extent exhibit 

 disturbances of a lower order, but still easily verified with a 

 pocket-compass. Such an area includes one or more centres 

 of violent local disturbance, and there appear to be evident 

 relations between the two orders of phenomena. Finally, it is 

 suggested that much smaller and more widespread disturbances, 

 such as those revealed by Riicker and Thorpe's magnetic 

 survey, may also be referable to permanent magnetisation of the 

 rocks. The alternative hypothesis of induction seems in- 

 adequate in view of the known geological constitution of the 

 district. 



Paris. 

 Academy of Sciences, February 26. — M. van Tieghem 

 in the chair. — On the law of diurnal rotation of the optical field 

 furnished by the siderostat and heliostat, by M. A. Cornu. It 

 is shown that the rotation of the field has the same period as the 

 diurnal movement, and is continuous and always in the same 

 sense. The field of vision of the siderostat remains absolutely 

 stationary when the polar distance of the star under examination 

 is equal to the supplement of the polar distance of the reflected 

 direction ; the field of the heliostat, when it can be used, turns 

 with an angular velocity which is always greater than that of 

 the daily movement.— On the composition of hydrofluoric acid 

 by volume, by M. Henri Moissan. Preliminary attempts were 

 made to make fluorine act directly upon a known volume of 

 hydrogen, but as the reaction proved to be too vigorous, the 

 fluorine was passed into water and the liberated oxygen, after 

 being freed from ozone by heating, measured. The fluorine 

 and hydrogen were found to be evolved on electrolysis in ex- 

 actly equal volumes. — Study of the serotherapy of anthrax, 

 by M. S. Arloing. Experiments carried out with the serum 

 upon sheep show that unless the serum is injected immediately 

 after infection with anthrax, no curative effects are produced, 

 thus rendering the serum of little practical value. Great differ- 

 ences were noticed in the effects when the injection of the serum 

 was made at different places, one cubic centimetre in the veins 

 having the same effects as ten times this amount injected into 



NO. 1584, VOL. 61 I 



the conjunctive tissue. — The new observatory of Tananarive, by 

 M. R. P. Collin. — The Perpetual Secretary announced to the 

 Academy the loss it had sustained by the death of M. Eug. 

 Beltrami, Correspondant for the Section of Mechanics. — 

 Observations of the Giacobini comet (January 31, 1900), made 

 at the Observatory of Paris with the 30*5 cm. equatorial, by M. 

 G. " Bigourdan. — Observations of the Giacobini comet (1900, a), 

 made at the Observatory of Besancon, by M. P. Chofardet. 

 — On the application of nomography to the prediction 

 of . occultations of stars by the moon, by M. Maurice 

 d'Ocagne. — On the method of Neumann and the problem 

 of Dirichlet, by M. A. Korn.— On the fundamental 

 kinematic equations of varieties in space of n dimensions, by 

 M. N. J. Hatizidakis. — On the movement of light waves and 

 the formuliie of Fourier, by M. Gouy. A discussion of some 

 recent papers of M. Carvallo upon the same subject. — The 

 interpretation ftf the thermomagnetic effect in the theory of 

 Voigt, by M. G. Moureau. — Remark on a recent note of M. 

 Th. Tomasina on the metallic crystallisation by electrical trans- 

 port of certain metals in distilled water, by M. D. Tommasi. 

 A reclamation of priority. — The association of molecules in 

 liquid bodies, by M. Daniel Berthelot. The author applies 

 his modified Van der Waal's formula, in which the co-volume 

 is regarded as a function of the temperature, to determine the 

 coefficient of association of liquids at the critical point. For 

 methyl, ethyl and propyl alcohols this coefficient is clearly greater 

 than unity, a fact which has been previously pointed out by Dr. 

 S. Young. — Oxidation by means of ferricyanides. Oxidation of 

 camphor, by M. A. £tard. The action of potassium ferricyanide 

 in alkaline solution is regarded by the author not as an addition 

 of oxygen, but a simple loss of hydrogen. Camphoric acid is 

 readily produced from camphor by this reagent. — On the an- 

 hydrous dimercurammoniun iodide in its amorphous and crys- 

 talline forms, by M. Maurice Francois. — On the estimation of 

 ammonia and of nitrogen, by MM. A. Villiers and E. Dumesnil. 

 The ammonia is distilled into an excess of hydrochloric acid, 

 evaporated to dryness, heated for twenty hours at 105°, and 

 weighed as ammonium chloride. It was found that even if the 

 period of final drying was prolonged to seventy-two hours, no 

 loss of weight occurred. — On the chemical equilibrium of a system 

 in which four gases are present, by M. H. Pelabon. The formulas 

 developed were tested experimentally by a study of the interaction 

 of mercury selenide and hydrogen at a temperature of 540° C. 

 The influence of pressure upon the constant obtained, which in 

 this case was considerable, was also studied. — On the contamin- 

 ated waters of the wells of Guillotiere and Brotteaux at Lyons, 

 by M. H. Causse. From the water from these sources, which 

 has caused typhoid fever, cystine was isolated. — Elimination of 

 sodium cacodylate by the urine after absorption through the 

 stomach, by MM. H. Imbert and E. Badel. — A new colour 

 reaction of tyrosine, by M. G. Deniges. Tyrosine treated 

 with aldehyde in a solution strongly acidified with sul- 

 phuric acid, yields a condensation derivative possessing 

 a fine rose carmine colour, with a characteristic absorption 

 spectrum.— On the rotatory power of active valeric acid, by M. 

 Ph. A. Guyeand Miss E. Aston. — On the plurality of species in 

 the cultivated red currant, by M. Ed. de Janczewski. — On the 

 parasitism of Phoma reniformis, by MM, L. Ravaz and 

 A. Bonnet. The authors conclude that the spores of P. reni- 

 formis cannot be the primary cause of the vine disease in the 

 Caucasus. — Examination of the fossils collected in China by 

 the Leclere mission, byM. H. Douville. — On the Oligocene of 

 the region between Issoire andBrioude, by M. J. Giroud. — The 

 denudation of the whole of the Lorraine plateau, and on some of 

 its consequences, byM. Bleicher. — On the comparative delivery of 

 the two kidneys, by MM. E. Bardier and H. Frenkel. — Action of 

 high-tension currents of high frequency upon chronic pulmonary 

 tuberculosis, by M. E. Doumer. Considerable improvement 

 followed the application of these currents to tuberculous sub- 

 jects, the nocturnal sweats being reduced after the fifth or sixth 

 application, and disappearing completetly after the fifteenth. 

 The feverish symptoms are reduced in about the same time, the 

 appetite commencing to improve after the fifteenth application. 

 The expectoration became less abundant, and in the few cases 

 that were systematically examined the number of bacteria 

 diminished. Occasionally, however, the numbers would in- 

 crease again. Sufficient time has not yet elapsed to be able to 

 speak of the permanency of the improvements noted. — The treat- 

 ment of tuberculous infection by muscular plasma, or zomo- 

 therapy, by MM. J. H^ricourt and Charles Richet. Curves are 



