May I, 19 19] 



NATURE 



179 



them with iron. An aqueous solution of ferrous am- 

 monium sulphate was the electrolyte used, and it 

 was found that, whilst excellent results could be ob- 

 tained from dilute solutions at the normal room tem- 

 perature, deposition could be carried out only very 

 slowly; with a concentrated solution, however, equally 

 jj^ood results were obtained at about seven times the 

 rate usable in the former case. Varying acidity of 

 the solution proved to have a great effect on the de- 

 posits, and the best results were given by an electro- 

 lyte made about 0005 normal with respect to sulphuric 

 acid. Bv heating the bath to a temperature of 

 60° C, deposition from a concentrated solution could 

 be carried out satisfactorily at a rate of up to fif!/ 

 times that which was possible in the case of the dilute 

 cold solution. Iron can be dep>osited direct on to 

 ■iteel, and subsequent heat-treatment produces an ad- 

 hesion of the deposit to the basis metal very much 

 better than the best attainable by simple plating, and 

 the deposited iron is much tougher than before treat- 

 inp- although it is considerably softer. Such deposits 

 can also be case-hardened with good effect. 



Dublin. 



Royal Dublin Society, April 15.— Prof. H. J. Sevmour 

 in the chair.— Dr. Joseph Reilly and E. Ralph • The 

 svstem M-butyl alcohol-acetone-water. The produc- 

 tion of a mixture of n-butyl alcohol and acetone on an 

 industrial scale by a fermentation process has rendered 

 desirable a knowledge of this system. Methods of 

 obtaining the composition of mixtures by a deter- 

 mination of acetone by a modification of Messenger's 

 method, and n-butyl alcohol by an adaptation of the 

 method of Verley and Bolsing for hydroxyl estima- 

 tion, are indicated. It was shown that the percentage 

 composition of mixtures is more readily found by 

 determination of a physical constant, such as specific 

 gravity, together with one chemical estimation. 

 Tables and curves drawn with both rectangular and 

 triangular co-ordinates, giving densities over a wide 

 range of mixtures are recorded. The limits of misci- 

 bility of fi-butyl alcohol and water were experimentally 

 found. 



Paris. 



Academy ol Sciences, April 7.— M. L^on Guignard in 

 the chair. — G. Bigourdan : The large instruments and 

 the work of Le Monnier at the observatory of the 

 rue Saint-Honor^. — E. Ariis : Formula giving the 

 density of a fluid in the state of saturation. — G. 

 Julia : Some properties of general meromorphic func- 

 tions. — N. Kryloff : Some approximation formulae 

 based on the generalisation of quadratures.^ — G. 

 Guillaumin : Ram-strokes in mains of variable dia- 

 meter and formed of conical parts. — L. Dunoyer : 

 A route-indicator for aerial navigation by dead 

 reckoning. — E. Aiilaire : The spontaneous inflamma- 

 tion of mixtures of air and ether vapour. After 

 testing mixtures of air and ether vapour at varying 

 temperatures in presence of a number of catalysts, 

 oxides of iron, copper, nickel, etc., the latter being 

 apparently without influence on the phenomenon, it 

 was found that spontaneous inflammation of a mix- 

 ture of air and ether commenced at about 190° C. 

 By working in tubes of larger diameter it is probable 

 that this inflammation would take place at a lower 

 temperature. The possibility of accidents in factories 

 where large quantities of ether are used, by contact 

 with pipes containing superheated steam, is pointed 

 out. — MM. Portevin and Garvin : The formation of 

 troostite at low temperatures in carbon steels and the 

 influence of the temnerature of immersion in inter- 

 rupted tempering. If the tempering of the steel is 

 interrupted by suddenly withdrawing the mass from 

 Ihe coolinsr-water, the temperature of the st^l is 



NO. 2583, VOL. 105] 



called the temperature of immersion. When the tem- 

 pering velocities are well above the critical velocities, 

 interruption of the tempering causes marked re- 

 calescence (80° C; at temperatures down to 450° C., 

 and troostite is obtained after cooling. — Ph. Glangeand : 

 The volcanic group of the Aiguiller, Monts Dore : its 

 secondary and peripheral volcanoes. — Ch. J. Gravier : 

 Pedogenesis and viviparity in the .Actinia. — E. Gravier : 

 Remarks on the preceding paper. — H. V, Vallois : 

 Some characters of the femur of Pithecanthropus. — 

 (i. Bertrand : The high toxic power of chloropicrin 

 towards certain of the lower animals, and the possi- 

 bility of employing this substance as a parasiticide. 

 Chloropicrin is readily made on the large scale, is 

 easily stored, and in concentrations of 001 to 0-12 

 gram per litre of air kills the larvae of various noxious 

 Lepidoptera and Hymenoptera. In solution in water 

 chloropicrin is equally very toxic for infusoria, and 

 will probably be of service for the partial sterilisation 

 of soils. 



April 14. — -M. Leon Guignard in the chair. — G. 

 Bigourdan : The works of Le Monnier on tfie stars 

 and physics of the globe. — A. Laveran : The artificial 

 acentrosomic varieties of Trypanosomes. In 1911 an 

 acentrosomic variety of Trypanosoma evansi was ob- 

 tained by the action of oxazine. This variety has 

 been cultivated through mice since 1911, and in April, 

 19 1 7, after the 450th passage, these organisms were 

 still acentrosomic! and there seemed good ground for 

 assuming that the disappearance of the centrosome 

 was definite and permanent. In .\pril, 1918 (870 pas- 

 sages through mice), the Trypanosomes still remained 

 acentrosomic, but an examination of the blood of the 

 mice in October, 1918 (the 945th passage), showed a 

 large number of Trypanosomes with well-defined 

 centrosomes. Finally, in January, 19x9, after 978 

 passages, all the centrosomes showed normal dimen- 

 sions. The result of this long experiment shows the 

 necessity for caution in dealing with a supposed 

 definite ^new variety produced in a living organism.— 

 M. Bigot was elected a correspondant for the section 

 of mineralogv in succession to W. Kilian, elected non- 

 resident member.— P. L6vy : The generalisation of 

 the Laplace equation in the functional domain. — E. 

 Bompiani : Quasi-asymptotic curves of surfaces in anv 



space. S. Xefschetz : .\belian varieties. — G. L. I« 



Cocq : A verv general property of cables used for 

 aerial transport.— P. Janet : ' .An electro-technical 

 analogv of sustained oscillations.— C. CWneveau and 

 R. Andnbert : Absorption by turbid media. .Applica- 

 tion to the estimation of suspensions.— P. Valllant : 

 Polarisation with alternating current.— F. Michaud : 

 The mechanical and osmotic action of radiant energy 

 on the media which it traverses.— A. Kling and R. 

 Schmutz : The characterisation and estimation of 

 carbon oxvchloride. A saturated aqueous solution of 

 aniline proved to be the best reagent for phosgene. 

 Diphenvlurea is quantitatively produced ; this is in- 

 soluble in water, and is readily characterised by its 

 crystalline form and melting point. The method may 

 be applied either to the estimation of carbon oxy- 

 chloride highlv diluted with air or in liquid com- 

 mercial phosgene.- A. Brives : The Suessonian tn 

 Central Morocco.- P. Bertrand : The plant zones of 

 the Coal Measures of the North of France.— P. 

 Prnvost : Comparison between the Coal Measures of 

 the North of France and those of Great Britain, 

 according to the succession of fauna.— L. Dunoyer and 

 G. RebonI : The utili«:ation of measurements of the 

 velocity of wind at different altitudes for the predic- 

 tion of barometric variations. When the wind velocity 

 is found to increase with the altitude, a fall of the 

 barometer is to be expected; conversely, if th^ velcx^ji- 

 ties decrease with the height, the barometer. yfjllrl^e. 



