October 29, 1896] 



NA TURE 



639 



probably clue to the fact that the instantaneous heat of conden- 

 sation is able to superheat the supersaturated steam as it arrives 

 at the surface. The velocity of condensation increases markedly 

 with the pressure ; and since the initial velocity of the jet and 

 ■ the rale of decrease of its velocity in ascending also increase 

 with the pressure, the amplitude of the oscillations decreases 

 with it.— Abnormal hickory nuts, by F. II. Ilerrick. The 

 author describes two hickory nuts of ordinary e.Klernal appear- 

 ance, but containing an endocarp strongly resembling an acorn, 

 and supposed to be cases of hyljridism between the oak and the 

 hickory. The minute anatomy of their structure gives no 

 direct evidence of hybridism, but the variation undoubtedly 

 arose at the lime of fertilisation, and is at present unexplained. 

 — Separation and identification of potassium and sodimn, by 

 I). A. Kreider and J. E. Breckenridge. These metals may be 

 -^ ftectivuly and delicately separated Ijy converting their salts inlo 

 (lerchlorales and precipitating the potassium with 97 percent, 

 alcohol. The sodium is ihen precipitated by blowing gaseous 

 liydrochloric .acid into the alcoholic fdtrate. — A new method 

 for reading deflections of galvanometers, by C. B. Rice. The 

 method is l)ased upon Gauss's mirror and scale method, but the 

 telescope is replaced by a lens at a short distance from the 

 mirror. The latter is perforated in the centre, and through the 

 hole is seen a black arrow on a white ground placed at an equal 

 distance beyond the mirror, which, being in the same plane as 

 ihe reflected scale, .serves as a pointer, and obviates the necessity 

 of a telescope. — The action of ferric chloride on metallic gold, 

 by r. C Mcllhiney. Ferric chloride by itself, or hydrochloric 

 acid in presence of air, have no action on gold. But a mixed 

 solution of hydrochloric acid and ferrii chloride dissolves gold 

 when oxygen is present, the ferric chloride acting as a carrier. 



Amerkan Journal of Mathematics, vol, xviii. Xo. 4, October- 

 — Mr. E. H. Moore concludes his tactical memoranda i.-iii- 

 with several more " whist-tournament arrangements," and 

 gives _a short list of the jniblished literature of the subject. — In 

 the Etude de Geometric Cinematique reglee, M. Rene de 

 Saussure proposes to establish a purely synthetical correspond- 

 ence entre les points de la surface imaginaire et les droites de 

 I'espace, de maniere a obtenir une gcometrie de I'espace regie 

 basce sur la geometric supposee connue, de la surface. He 

 discusses first the principles of the synthetic geometry of such a 

 space, and then the kinematic geometry of the same space. 

 He next gives applications of his theory. In this theory la 

 ligne droite est prise comme element d'espace, non-seulement 

 au point de vue geometrique, mais aussi au point de vue 

 niecanique ; cette maniere devoir conduit a la conception d'lnie 

 iiiUmatii/tie regh'c. La raison d'etre de cette branche de la 

 cinematique provient du fait que le deplacement le plus gener.al 

 d'un corps solide est une torsion et I'effort le plus general exercc 

 sur un solide est ce que Pliicker api^elle un dyname et Ball un 

 torseur (wrench) ; car Tefibrt que developpe un dyname ou un 

 torseur s'exerce sur une droite de nieme qu'une force s'exerce 

 sur un point, puisque le vectangle est a la droite ce que le 

 vecteur est au point. — The volume closes with a paper by 

 Goursal, entitled '• Sur les equations lincaires et la methode de 

 Laplace." In it the author develops, at some length, a recent 

 note which he presented to the Academy of Sciences { Coinplis 

 leiiJns, t. cxxii. , January 27, 1896). 



SOCIETIES AND ACADEMIES. 



P-VRIS. 



Academy of Sciences, (Jctober 19. — M. A. Cliatin in the 

 chair. — The President announced the death of M. Trecul, Mem- 

 ber of the Botanical Section, on October 15.— New researches 

 relating to the decomposition of sugars, under the influence of 

 acid-^, and especially with the production of carbonic acid, by 

 MM. Berthelot and G. Andre. The experiments were ]iartly 

 conducted in .sealed tubes at 100 , partly in open flasks, at the 

 boiling point. Estimations were made of carbonic acid, carbon 

 monoxide, formic .acid, levulic acid, humic acid, and unaltacked 

 ghicosc. Besides glucose, experiments were carried out with 

 levulose, galactose, and maltose. The principal reaction appears 

 10 be the formation of humic acid ; carbonic acid is also formed 

 in not inconiiiderable quantity. — Determination of the magnetic 

 elements at sea. Applications of the observations made by M. 

 Schwercr on the Duhourdicii, by M. E. Guyon. Since the 

 formula; developed by ArchibaUl Smith and by Biirgen for 



NO. 1409, VOL. 54] 



correcting the readings made at sea, were worked out for ships 

 into the construction of which comparatively little iron entered, 

 it became necessary to make a fresh study of the corrections 

 to be applied to readings taken upon warships as built at 

 present. In the method here indicated all the constants neces- 

 .sary for the corrections for each kind of observation (declination, 

 inclination, and total force) are deduced exclusively from 

 observations of the same nature. — On the work carried out at 

 the Observatory of Mount Blanc in 1S96, by M. J. Janssen. 

 The work has been considerably impeded by the bad weather 

 jirevailing, the actinometric observations being especially inter- 

 fered with. The large telescope (33 cm. diameter) has been 

 successfully mounted, and the observations on the values of the 

 acceleration due to gravity at different points on the mountain 

 have been continued. — Study of the digestibility of cocoa- 

 butter and ordinary butter, by MM. Bourot and F. Jean. 

 Comparative experiments carried out with the same person 

 showed that 95'S per cent, of ordinary butter is digested, and 

 98 per cent, of cocoa-butter. An abnormally large quantity of 

 fat in the food causes less disturbance if the fat is cocoa-butter 

 than if it is present as ordinary butter. — Some colour reactions 

 of brucine : detection of nitrous acid in presence of sulphites, 

 by M. P. Pichard. The red colouration produced in an acid 

 solution of brucine by a nitrite is capable of showing one part 

 of nitrous acid in 640,000 parts of water, and is more sensitive 

 in the presence of sulphites and hyposulphites than the tests 

 proposed by Griess, Tromsdorfi", and Piccini.— tjeneral principles 

 relating to the physics of space, by M. J. Poulin. — Tempests 

 and cyclones, by ]\I. A. de Langree. — Note on aerial navigation, 

 by M. Caravanier. — On some |)eculiarilies of solubility curves, 

 by M. H. Le Chatelier. Some experiments on the melting 

 points of some double salts and alloys, showed that in the 

 neighbourhood of the composition corresponding to a definite 

 combination (SnCua, SbCuj, Af.Cu, &c.), the curve showed a 

 maximum temjierature in the form of an angular point, which 

 did not necessarily correspond exactly to the point of definite 

 composition. The theoretical discussion elucidates the reason 

 for this peculiarity. — Influence of pressure- in the changes of 

 state of a body, Ijy M. A. Ponsot. — On the property of 

 discharging electrified conductors, produced in gases by the 

 X-rays and by electric sparks, by M. E. Villari, It is shown 

 that a gas confined in a tube, and exposed to the X-rays, acquires 

 rapidly the power of discharging an electrified disc, and keeps 

 this property for some time. The passage of a series of sparks 

 from a coil strengthened by a condenser, confers the same 

 property upon a gas. — On the action of the silent discharge upon 

 the property of gases of discharging electrified conductors, by M. 

 E. Villari. Gases subjected to the action of a series of sparks 

 acquire an increased conductivity for heat. The silent discharge 

 is not able to put the gas into the condition in which it can dis- 

 charge an electrified body, but if a gas which has been subjected 

 to X-rays, and which therefore is in this condition, is subjected to 

 the silent discharge, it is no longer able to affect a charged gold- 

 leaf electroscope. — Succession of the atomic weights of the ele- 

 ments, by M. Delauney. An attempt to classify the elements 

 according as their atomic weights are expressed by : 4«, 

 4« -H 3, 4« -I- 2, or 4« -I- I. — Phosphopalladic ethers. Am- 

 moniacal derivatives of phosphopalladous and phosphopalladic 

 ethers, by M. Finck.— Law of the establishment and persistence 

 of the luminous sensation, deduced from new experiments upon 

 rotating discs, by M. Charles Henry.— On the jaws in insects, 

 by M. Joannes Chatin. — On the habits of Evania Desjarduisii, 

 by ]\L E. Bordage. — New observations on the bacteria of the 

 potato, by M. E. Roze. — Some remarks on the kerosine shale of 

 New South Wales, by M. C E. Bertrand.— On the micro- 

 granulites of the Ferret valley, by MM. L. Duparc and F. 

 Pearce.— On the mode of formation of the Pyrenees, by M. P. 

 W. Stuart-Menteath. — Contribution to the theory of the move- 

 ments of storms, by M. J. Vinot. 



.\.\ISTEKD.\M, 



Royal Academy of Sciences, September 26. — Prof. 

 Stokvis in the chair.— Prof Kortcweg, who, as delegate of the 

 Dutch tJovernment, attended the I-loyal Society conference on the 

 desirability of preparing a catalogue of scientific works, spoke 

 of this conference, and entered into some details concerning its 

 purpose, the nature of the resolutions passed, the task of the 

 national bureaux, and the arrangement of the subject-index. 

 Prof Haga exhibited two negatives which prove the existence 

 of different kinds of X-rays, a conclusion also arrived at by 



