March 24, 192 1] 



NATURE 



12' 



Exogenous xygomorphosis in flowers normally actino- 

 morphs. — G. Cerf : Certain systems of Pfaff equations 

 and the transformations of partial differential equa- 

 tions. — D. Riabouchinski : The initial movement of 

 a liquid in contact with an obstacle with sharp edges. 

 — A. Danjon and G. Rougier : The re-appearance of 

 Saturn's ring, observed at the Observatory of Stras- 

 bourg, February 22, 192 1 (see p. 119). — F. M. de Laro- 

 quette and S. Miilot : Experimental data and balance 

 for the estimation of X-rays in radiography and radio- 

 therapy. — M. de Broglie : The corpuscular spectra of 

 the elements. — M. Pariselle : An achromatic triplet with 

 a large field. — C. Matignon : The action of iodine on 

 different metals in the cold. A method for detecting 

 the presence of chlorine in the atmosphere. Metals 

 in thin foil are converted into iodides by contact with 

 iodine. A piece of silver foil coated with potassium 

 iodide forms a delicate test for the presence of chlorine 

 in air; the foil forms part of an electric circuit, 

 chlorine sets free iodine, and the silver iodide imme- 

 diately formed is a non-conductor. — A. C. Vournazos : 

 The bismuthobromocyanides. — M. Chapas : The solu- 

 bility of the isomeric nitroanilines in metaxylene. 

 These isomers differ greatly in solubility, at 15° C. 

 the proportions being- ii-6, 174, and 0-28 per' cent, 

 for the ortho-, meta-, and para-compounds respectively. 

 — O. Mengel : Relations between earthquake pheno- 

 mena and the structure of the Pyrenees.^G. Guilbert :' 

 A case of destruction by a gale. Various applica- 

 tions of meteorological rules published by the author 

 in earlier communications. Several examples are 

 given in which predictions based on these rules have 

 been justified in detail.— A. Lumiere : Surface tension 

 and anaphylactic shock. Criticism of a recent paper 

 bv W. Kopaczewski. Measurements by the author of 

 the relative surface tensions of water. 5 per cent, solu- 

 tion of sodium hyposulphite, blood serum, and the 

 last diluted with an equal volume of sodium hypo- 

 sulphite solution, do not agree with the corresponding 

 measurements made by W. Kopaczewski, and hence 

 the hypothesis of the latter as to the intervention of 

 surface tension in the production of the anaphylactic 

 shock is not confirmed.— A. Paillot : Contribution to 

 the study of humoral immunity in insects. — G. Bertrand 

 and A. Compton : The influence of heat on the activity 

 of salicinase. It is known that the activity of a 

 diastase increases with the temperature, passes 

 through a maximum, and finally decreases to nothing. 

 The most favourable temperature and the temperature 

 at which activity ceases have been frequently treated 

 as physical constants of a ferment, analogous with the 

 melting point and boiling point of a definite substance. 

 It is shown, however, that these two temperatures 

 cannot be considered as constant, since they can be 

 made to vary with the experimental conditions, the 

 most important being the time during which the 

 diastase is allowed to act. The results of a series of 

 experiments on salicinase are given graphically in two 

 curves, the ordinates being temperatures and the 

 abscissae duration of the action. With salicinase the 

 two curves meet at 70° C. ; this is the temperature 

 of maximum activity, and also the highest tempera- 

 ture at which diastase can exist.— A. Desgrez and R. 

 Moog : The influence of some organic bases and of 

 their chlorohydrates on the activity of pancreatic 

 amvlase. The bases triethylamine and trimethvlamine 

 reduce the diastatic activity, but the chlorohydrates of 

 these and of methvlamine exert a contrary action and 

 increase the activity of pancreatic amylase. — H. 

 Grenet, H. Dronin, and M. Caillard : The study of 

 some leucocvtic reactions following on intravenous 

 iniections. — H. Frossard : The detection of thoracic 

 vibrations in women and children in pleurisy. 



NO. 2682, VOL. 107] 



Rome. 



Reale Accademia nazionaie dei Lincei, November 21. — 

 F. D'Ovidio, president, in the chair. — B. Grassi : Life 

 of Anopheles, i. — A. Comessatti : Geometric theory of 

 binary forms, i. This part deals with directive ideas 

 and their first consequences. — A. Denjoy : " Sur les 

 ensembles parfaits presentant le caract^re (A)." — 

 E. Clerici : New mineral deposit near Rome. 

 The author records the presence of fluorite and 

 barytes in calcareous deoosits near the Villa 

 Farnesina and the tomb of the Nasoni. — A. 

 Contardi : Transformations of trioxymethylene. — 

 B. Peyronel : Ascophorous form of Rhacodiella cas- 

 taneae, the cause of smut in the chestnut. The author 

 has succeeded in cultivating the perfect stage of this 

 fungus, which he refers to the genus Sclerotinia. — A. 

 Clementi : Relation between the peptidolitic activity 

 of intestinal erepsin and the chemical constitution of 

 the substratum.— U. Soli : Bactericidal power of 

 intestinal mucus. 



December 5. — V. Volterra, vice-president, in the 



chair. O. M. Corbino : Thermal analogue of 



Oersted-Ampere effect and electronic theory of 

 metals. — B. Grassi : Life of Anopheles, ii. A number 

 of specimens were dved and set free, and from their 

 disappearance it was' inferred that the summer broods 

 live only about ten days to a fortnight. The author 

 now discusses the question as to whether the insects 

 tend to return to the localities where they have 

 already bitten. The results are sufficiently definite 

 to explain why malaria does not spread more fre- 

 quently to nonlinfected districts, and to show that it 

 is more important to kill the mosquitoes in houses, 

 particularly those containing malarial cases, than in 

 such locali'ties as pigsties.— A. Comessatti : Geometric 

 theory of binary forms, ii. This part deals with the 

 theorem of Bruno and conic co-variants.— E. Del 

 Vecchio : Theorems of uniqueness for parabolic linear 

 differential equations of third order, i.— A. Denjoy : 

 " Les rapports des ensembles parfaits presentant le 

 caract^re (A) et des fonctions admettant une d^rivee 

 seconde g^neralisee."— M. Pascal : Superficial circula- 

 tion, i. The ordinary conception of circulation round 

 a closed curve is generalised, leading to a measure 

 of circulation in the form of a surface integral over 

 a closed surface. This is a vector which satisfies the 

 usual laws of composition and resolution. The exten- 

 sion of problems from two to three dimensions is 

 contemplated, with especial reference to^ Joukowski's 

 theorem, according- to which cyclic motion in a per- 

 fect fluid surrounding a moving body gives sustenta- 

 tion without resistance.— A. Terracini : A surface of 

 the sixth order and class the asymptotics of which are 

 skew cubics. — R. Perotti : Radical bacilli of Diplotaxis 

 erticoides. Three forms of bacilli found on the DiplcK. 

 taxis roots are described which possess the property 

 of attacking and transforming insoluble carbohydrates 

 such as starch. Their action is not pathogenic, and 

 whether thev belong to three species or one is left 



open. G. Cnsmano : Intermolecular condensations 



produced by oxynitric groups. The author discusses 

 the actions of concentrated sulphuric acid on o-amino- 

 nitroxvbenzol and the action of alkali on o-hydroxyl- 

 aminonitroxvbenzol.— The Academy has elected Drs. 

 Pirotta and Lanciani to the offices of administrator 

 and assistant administrator respectively. 



December 19. — F. D'Ovidio, president, in the 

 chair. — G. A. Maggi : Propagation of waves of 

 arbitrary form in isotropic media. A mathematical 

 investisration dealing with objections to Prof. 

 Somigliana's proof, according to which only plane, 

 cylindrical, or spherical weaves can be propagated in 

 an isotropic medium subject to the usual conditions. — 



