5i6 



NATURE 



[December 15, 1921 



Jeflery : The electrolysis of aqueous solutions of alka- 

 line nitrites with a lead anode and an electrometric 

 determination of the constitution of the complex 

 anion formed. The plumbo-nitrite complex is 

 (Pb(N02)4)" for small concentrations of lead in alkali 

 nitrite solutions. Probably this is the only complex 

 formed. The solid in equilibrium with solutions ob- 

 tained from anolytes of certain concentrations is lead 

 nitrite crystals, Pb^NOi)^,!!^©. The colour of these 

 crystals is approximately the same as that of the solu- 

 tions from which they are derived, showing that the 

 plumbo-nitrite complex probably maintains its identity 

 in the crystals. A direct way of testing this hypo- 

 thesis would be bv an X-ray analysis of the crystals ; 

 the (Pb(N02)4) group should form a pattern regularly 

 repeated in three dimensions relative to the cationic 

 Pb atoms. — T. C. Nugent : An inhibition period in 

 the separation of an emulsion. The system investi- 

 gated was a fairly concentrated emulsion of benzine 

 in water containing known amounts of stabiliser, 

 i.e. gelatin or gum arabic. If caustic soda solution 

 is added immediately, then the separation of the ben- 

 zine commences immediately; but if the emulsion 

 is left undisturbed for some time before the caustic 

 soda solution is added, the separation of the benzine 

 is retarded. This time lag may be termed the "in- 

 hibition period." Probably after an emulsion is pro- 

 duced, the gelatin slowly forms protecting layers 

 about the benzine particles, and therefore the stability 

 of an emulsion increases with its age. — N. R. Dhar 

 and N. N. Mittra : Induced reactions and negative 

 catalysis. Induced reaction is proved to be of general 

 occurrence. In oxidation reactions, negative catalysis 

 takes place when the catalyst is readily oxidisable. 

 The explanation offered is the hypothesis of the 

 formation of intermediate compounds. Experimental 

 evidence supports the view that one chemical change 

 will either promote or induce another chemical change 

 of the same nature. 



Linnean Society, December i. — Dr. A. Smith Wood- 

 ward, president, in the chair. — W. Neilson Jones : 

 Note on the occurrence of Brachiomonas. This alga, 

 which appeared last year in rain-water pools at 

 Regent's Park College, had previously been reported 

 only from brackish water at Sheerness, Stock- 

 holm, and the Black Sea.— J. Burtt-Davy : The dis- 

 tribution of Salix in South Africa. In South Africa 

 ten species or varieties are known, and in tropical 

 Africa twelve, only one being common to both areas. 

 Usually each species occupies limited areas in 

 one particular drainage-basin, so fhat cross-pollination 

 is practically impossible. 5. VJood-ii may be the con- 

 necting-link by way of Pondoland, the Transkei, and 

 Eastern Cape with S. sajsaf in Rhodesia. Although 

 the Orange River is isolated from Angola by the 

 wastes of the Kalahari, it is possible that these 

 species, or a common ancestor, came from the north 

 when the Cunene discharged into the Orange by wav 

 of the Molopo. — M. Christy : The oroblem of the pol- 

 lination of our British Primulas. Some thirty species of 

 insect visit or frequent the flowers of the three British 

 Primulas (P. vulgaris, P. veris, and P. elatior). A 

 small proportion have long tongues and are able to 

 effect pollination, but their visits to the flowers are 

 comparatively rare, and inadequate for the perpetua- 

 tion of these Primulas. Most other insect visitors 

 are short-tongued bees, totally unable to effect pol- 

 lination. Some Coleoptera frequented the flowers, and 

 seem capable of pollinating them, though in an ir- 

 regular manner. Night-flving moths were suggested 

 as the agents of normal pollination — a surmise advanced 

 by Darwin. 



NO. 2720, VOL. 108] 



Paris. 



Academy of Sciences, November 28. — M. Georges] 

 Lemoine in the chair. — P. Termier and L. Joleaud 

 New observations on the "nappe de Suzette " formed 

 of Triassic strata, issued from the Alps, and having, 

 covered at the Aquitanian period a part of the region 

 of the Rhone. — P. A, Dangeard : The nature of the 

 spherome in the plant-cell. Reply to a recent com- 

 munication by M. Guilliermond. — G. Mittag-Leffler ; 

 Cauchy's theorem on the integral of a function 

 between imaginary limits. — M. de Sparre : The yield 

 of reaction turbines working under a variable load. 

 Turbines are usually constructed to work under full load. 

 Calculations are given for determining the efficiency 

 under a reduced load, and also for modifying the 

 design of the turbine, so that while sacrificing a 

 small percentage of efficiency at full load the effi- 

 ciency varies only slightly under large variations of 

 load. — C. Sauvage'au and G. Deniges : The efflorescence 

 of marine algae of the genus Cystoseira. — G. Cerf : 

 The systems of Pfaff and the transformations of partial 



differential equations. — J. Wolff : The series Z ■. 



2~at 1 



— E. Borel : Remarks on the preceding note. — G. \ 

 Valiron : Integral functions and their inverse functions. '. 

 C. Camiciiel : Hydraulic states of flow. — D. Eydoux : 

 The variation of energy round a point of a rotating 

 hydraulic machine. — G. Fontene : The two Lorentz 

 coefficients of inertia for movements at high velocities. 

 . — E. Belot : The minor planets of the Saturn family. — 

 Mrs. Isaac Roberts : A star which may have appeared 

 in the sky since 1892. — J. Le Roux : Time in classical 

 mechanics and in the theory of relativity. — A. 

 Dauvillier : Analysis of the atomic structure. The 

 author summarises the conclusions derived from his 

 theory of atomic structure in a form of the periodic 

 table of the elements, showing the number of the 

 superficial electrons, the number of electrons, and the 

 quanta. — E. Rengade : The resolution of a salt in the 

 course of the isothermal evaporation of a solution. 

 Reply to a criticism of M. Raveau. — A. Kling and A. 

 Lassieur : The separation and estimation of copper, 

 lead, antimony, and tin. The analysis of white 

 metals. The method Is based on the conversion of 

 the tin into a complex stannl-fluorlde, from which the 

 sulphide is not precipitated by sulphuretted hydrogen, 

 with later application of rapid electrolytic methods. — 

 P. Ttiomas and G. Carpentier : A very sensitive re- 

 agent for copper : the Kastle-Meyer reagent. This 

 reagent, an alkaline solution of phenol phthalein, 

 originally proposed as a test for blood, is an extremely 

 sensitive reagent for copper, and will show one part 

 of copper In a hundred millions of water, and as 

 ordinary distilled made with a copper still may con- 

 tain one part of copper in a million, special pre- 

 cautions are necessary in applying the test. In a 

 solution free from organic compounds the reaction Is 

 distinctive, and Is given by no other metal. — P. Robin : 

 The action of nitrogen iodide and cyanogen iodide on 

 benzamldlne. — C. Mariller : A method of fractionating 

 liquid mixtures and Its application to the preparation 

 of a home-produced fuel.— P. Gaubert : The re- 

 crvstalllsation produced by annealing. The theories 

 which have been put forward to explain the re- 

 crystallisation of metals have been applied to Inter- 

 pret the results of experiments on organic compounds, 

 vanillin, paraffin wax, beeswax, and cetin. It was 

 found that recrystalllsatlon Is, In general, only pos- 

 sible when the cr^-stals are sufficiently malleable for 

 mechanical actions to modify their crystalline net- 

 work. — P. Glangeaud : The architecture of the three 

 principal volcanic centres of the Cantal massif. — P. 

 Corbin : The tectonic of the eastern edge of the 



