SOCIETY OF PHYSICS AND NATURAL HISTORY OF GENEVA. 369 



exist? in bodies. To express tliis progressive change M. Clausius imagines a 

 magnitufle which, in rchition to the transformations, wouhl \)\i\y the same part 

 as heat in rchition to energy and work, and he calls this magnitadc cntropic. 

 The result of his philosophic views he ex})rcsses by saying that the entropy of 

 the universe tends towards a maximum. Thus the modifications und(;rgone l>y 

 the creation, instead of having a periodical and circular course, always take 

 place in a definite direction and tend towards a limitary state. If that state ho 

 some day attained, no ulterior change will he possible, and the univovso will 

 lapse into a condition of persistent death ! 



M. Charles Cellerier presented (May 7) two notes; one relating to the theory 

 of prime numl»ers, of Avhich a mean law may be found more approximuto than 

 that indicated by Legendre ; the otlier devoted to the calculation of the attractions 

 and repulsions in electrilied bodies. M. Cellerier demonstrates that, whatever be 

 the form and arrangement of several insulated conductors, the total potential 

 possesses for each of them, at every instant, a constant value in its whole interior. 

 Moreover, if we compute the sum of the products of the potential of each con- 

 ductor by the total mass of the electricity which covers it, the variable quantity 

 thus ol)tained has the property of representing double the labor of the forces 

 exerted on the material conductors themselves, when these are displaced in any 

 manner. The calculation for the special case of two spheres serves for contirma- 

 tion to this general theorem. 



Some communications were also made by your president. He exhibited a 

 sample of the infusion of Cuba wood, or braziline, discovered by Professor Gop.- 

 pelsroder, which is endowed with a very decided fluorescence. He submittetl 

 to 3'Our notice the new magnifying glasses of Adolphe »Steinheil, formed Ivy tk© 

 conjunction of three lenses, and possessing the double advantage of being rtclu'o- 

 matic and of not destroying the images on the contour of the visual ii(!Ut. He^ 

 described the electro-magnetic pendulum of Tiede, which has served l\t>ft>t<soi- 

 Forster, director of the Astronomical Observatory of Berlin, to deterusine the 

 coiTcction which should be applied to the speed of a clock for the variations of 

 the atmospheric pressure. He presented the new electric machine of Holtz^ autl 

 repeated the unpublished experiments of M. Ktinig on the determimitlou of tho 

 upper limit of sounds perceptible from the concussion of bars of steel cnlculattx;! 

 by length. He called attention to a singular case of permanence in a charge of 

 electricity induced in a long wire, a case observed in England by M. Wild. H« 

 pointed out an elementary solution of the problem of the trisectvau of the angle. 

 Finally, he described experiments which he had made with the improved reg«- 

 lator of Leon Foucault for the electric light. These researches confirm iho 

 results which he communicated to the; society in 1852, namely^ that with abattwy 

 which works well and a delicate apparatus, the cm-rent may be interrupted duai;t<^ 

 one-thirtieth of a second without inducing variation in the illuminatiou of a serct^u 

 exjiosedtothelightof thearc. The armature of the electro-uiagnet is not unchai^x\l, 

 and no sound of any action is heard. If the interruiitiouis longer continued, )x>tU 

 the eye and the ear are apj)rised of it. "When the interruption attains one-teuth 

 of a second the arc vanishes, I conclude from this, and from considen^tionsi 

 which would detain us too long if detaihxl here, that when the intcrru))tii)u is 

 pulliciently short, the arc continues to exist, contrary to the ojjinion of M. F. i*. 

 Jjcroux, who recognizes a cessation followed by the spontaneous re-establish- 

 ment of the arc. {Comptcs licndus de VAcad^mie dcs IScienccs dc JPari^; t. Ixvi, 

 p. 155.) 



§ 4. — CIIEMISTKT. 



i\r.Delafontainchas ascertained (21st jSTovember) that the mcdybdafos dissolved 

 in fluorhydric acid give rise to a now class of salts, the iluoxymolybdates, which 

 present the most complete analogy with the fluoxytungstates and the fluosynio- 

 24 s 



