February 26, 1903] 



NA TURE 



407 



being subjected to a partial vacuum, again from the back, 

 portions of the design were seen to be darker than the 

 surrounding surface, but bordered with a light fringe. It 

 appears now to be thoroughly established that the cause 

 of the " magic " effect in Japanese mirrors is due to the 

 unequal resistance to flexure during the polishing process. 



Paris. 



Academy of Sciences, February 16. — M. Albeit Gaudry 

 in the chair. — The President announced to the Academy 

 the death of Sir George Gabriel Stokes, foreign associate. — 

 A law relating to the electromotive forces of batteries based 

 on the reciprocal action of saline solutions and soluble electro- 

 lytes, by M. Berthelot. — A direct and simple calculation of 

 the velocity of propagation of a wave front in a medium 

 having complicated equations of motion, by M. J. 

 Boussinesq. — On the radiation of polonium and radium, 

 by M. Henri Becquet-el. In a previous paper the author 

 has shown that the a-rays of Rutherford, which are probably 

 identical with the Kanalstrahlen of Goldstein, are capable 

 of a slight deviation in a strong magnetic field. The present 

 paper is devoted to a proof of the existence of a correspond- 

 ing property in the radiation from polonium. Owing to 

 the very slight photographic action of the specimen of 

 polonium under examination, the action had to be prolonged 

 for twenty hours. The same apparatus was used for com- 

 parative experiments with radium. The two photographic 

 proofs, the one with radium and the other with polonium, 

 appeared to be superposable, thus proving the absolute 

 identity under the conditions of the experiment of the 

 a-radium rays and the polonium rays. In neither case was 

 there any trace of dispersion analogous to that observed with 

 the kathode rays. — On some new syntheses effected by means 

 of molecules containing the methylene group associated with 

 one or two negative radicles. The action of epichlorhydrin 

 on the sodium derivatives of acetone-dicarboxylic esters, by 

 MM. A. Halici- and F. March. The sodium derivative of 

 acetone-dicarboxylic acid condenses readily with epichlor- 

 hydrin, giving a keto-lactone, the properties of which, with 

 those of its semicarbazone, are described. — Approximate 

 algebraic expressions for transcendental, logarithmic and 

 exponential functions, by M. J. A. Normand. A series of 

 formulas is developed permitting of the rapid calculation 

 of the numerical value of logarithms. Numerous examples 

 showing the degree of approximation are appended. — Re- 

 marks by M. Considere on a memoir on the resistance 

 of armed mortars. — M. Rene Benoit was elected a corre- 

 spondant in the section of physics in succession to the late 

 Prof. Rowland. — The eruption of Mont Pelee in January, 

 1903, by M. A. Lacroix. — Perturbations independent of the 

 eccentricity, by M. Jean Mascart. — Researches on electro- 

 lytic valves, by M. Albert Nodon. The term electrolytic 

 valve is applied to an electrolytic cell for the conversion of 

 an alternating current into a unidirectional current. Metals 

 having a low atomic weight, such as magnesium or 

 aluminium, are the best for this purpose, and a solution of 

 ammonium phosphate forms the best electrolyte. The 

 electrostatic capacity of these cells is considerable, about i 

 farad p*er square centimetre of surface of aluminium, the 

 thickness of the dielectric which forms the condenser being 

 of the order io -8 , or of molecular order. Such a cell may 

 be successfully applied to the rectification of telephone 

 currents, and can be used for their measurement. — On the 

 induced radio-activity produced by salts of actinium, by 

 M. A. Debierne. It is known that the compounds of radium 

 possess the property of rendering bodies placed in their 

 vicinity temporarily radio-active. Actinium salts possess 

 the same property, the effects produced presenting the same 

 general characters as with radium. There are, however, 

 differences distinguishing the action of the two elements. — 

 The conditions of estimation of manganese in acid solution 

 by persulphates, by M. H. Baubigny. A series of determin- 

 ations is given, showing the effect of the nature of the acid, 

 its quantity and the amount of persulphate used. — The heats 

 of formation of some sulphur and nitrogen compounds, by 

 M. Marcel Delepine — The action of hydrogen upon silver 

 sulphide in the presence of the sulphides of antimony and 

 arsenic, by M. H. Pelabon. — The action of phosphoric acid 

 upon erythritol, by M. P. Carre. Phosphoric acid acts 



NO. 1739, VOL. 67] 



upon erythritol firstly as a dehydrating agent, and then 

 forms a mono-ester of erythrane. A portion of the latter is 

 converted into a di-ester. — The preparation of some com- 

 binations of a-methyl-a-isopropyl-adipic acid, by M. C. 

 Martine. — On the temperature of calefaction, and on its use 

 in alcohol determinations, by M. Bordier. The term point 

 of calefaction is applied to the temperature at which contact 

 ensues between a hot plate and a drop of liquid in the 

 spheroidal state. In the case of mixtures of alcohol and 

 water this temperature is a function of the composition, and 

 the use of this method is suggested as a means of determin- 

 ing the amount of alcohol in solution. It has the advantage 

 of requiring only a very small quantity of liquid. — On the 

 pathogenic action of the rays emitted by radium on different 

 tissues and organisms, by M. J. Danysz. The action is 

 most intense on the skin, the action being relatively slight 

 upon the underlying tissue and attached muscle. The 

 nervous system is especially sensitive to the action of the 

 rays. The larva? of insects exposed to the rays were para- 

 lysed in twenty-four hours and died two days later. — The 

 mechanism of the action of secretin on the pancreatic secre- 

 tion, by M. C. Fleig. The experiments given tend to show 

 that secretin acts directly upon the pancreas, either acting 

 directly upon the pancreatic cell or on the excito-secretory 

 elements. Secretin, contrary to the views of Popielski, 

 offers a good example of special chemical substances which, 

 by their diffusion in the blood current, establish relations 

 between certain determined organs. — The action of the 

 fundamental vibrations of the vowels on the ear in a patho- 

 logical state, by M. Marage, — On the implantation of dead 

 bone in contact with living bone, by MM. V. Cornil and P. 

 Coudray. Dead bone remains very nearly in the condition 

 in which it was implanted, embedded in a fibrous capsule. 

 It behaves almost like a foreign body, its resorption, even 

 at the end of six months, being insignificant. — On Chataig- 

 nier's disease, caused by Mycelophagus Castaneae, by M. L. 

 Mangrin. — A new genus of Chytridiacese, by M. P. A. 

 Dangeard. — Phenomena of transportation in the eastern 

 Mediterranean, by M. L. Cayeux.— The absorption of 

 ammonia by sea-water, by M. J. Thoulet. 



New South Wales. 

 Royal Society, December 3, 1902. — Prof. Warren, presi- 

 dent, in the chair. — On the occurrence of an important 

 geological fault at Kurrajong Heights, Blue Mountains, 

 by Prof. T. W. Edgeworth David, F.R.S. Traced 

 in a southerly direction across the Grose Valley to 

 Glenbrook Railway Station, the fault dies out, pass- 

 ing into a gentle westerly fold, which does not 

 appear to have been accompanied by shearing. To the 

 east is the well-known steep easterly monocline. Traced 

 northerly, the monocline crosses Grose Valley and forms 

 the eastern slope of Kurrajong Heights. The monocline at 

 the Kurrajong is bounded westwards by an abrupt fault, 

 whereas at Glenbrook the line of disturbance takes the 

 form of a gentle fold facing the west. The fault plane, 

 though somewhat eroded, still forms a steep and very con- 

 spicuous escarpment. The effect of this fault in displacing 

 the Coal-measures on either side of it will obviously claim 

 the serious attention of those who, in the future, have 

 charge of coal mines in that portion of our coalfields. — 

 Investigations in regard to the comparative strength and 

 elasticity of Portland cement, mortar and concrete, when 

 reinforced with steel rods and when not reinforced, by Prof. 

 W. H. Warren. The paper describes experiments on 

 various mortars and concrete in tension and compression, 

 also wJien subjected to bending stresses. The extensions of 

 the specimens subjected to direct tension when reinforced 

 with steel rods were considerably less than occurred in 

 similar specimens not reinforced ; the stress-strain diagrams 

 plotted from the observations taken were all convex to the 

 stress axis, but the curve was much flatter for the rein- 

 forced specimens. The transverse tests consisted of experi- 

 ments with beams reinforced on the tension side with steet 

 rods, compared with similar beams not reinforced. In aP 

 cases the reinforced beams were from 5J to 10 times stronger 

 than the plain beam, and the deflections of the beams before 

 fracture were enormously greater in the reinforced beams. 

 — The fallacy of assuming that a wet year in England wiil 

 be followed by a wet year in Australia, by H. C. Rueee'il, 



