June 6, 1907J 



NA TURE 



143 



rompounds in acetic acid solution, the crystalline product, 

 which is first formed, yields, on pouring it into water, the 

 nuclear brominated compound. This intermediate com- 

 pound has been isolated in the case of aceto-/)-toluidide. 

 The following provisional explanation of the action is 

 offered : — 



Me 



NH.COMe->Mes/ 



>-NH.COMe- 

 Br 



Me/ ^NBr.COMe->Me' )NH.COMe. 



' bT 



— Mixed semi-ortho-oxalic compounds : G. D. Lander. 

 The amide chlorides of methyl and ethyl oxanilates are 

 stable below ioo°. On decomposition by heat they pass, 

 by loss of hydrogen chloride, into the imide chlorides, which 

 are further resolved into alkyl chloride, carbon monoxide, 

 and phenylcyanate. — Some derivatives of 7-pyranol allied 

 to certain derivatives of brazilein and hoematein. Pre- 

 liminary communication : W. H. Perkin, jun., and R. 

 Robinson. o-Hydroxybenzaldehyde and its derivatives 

 condense with certain acetophenone or hydrindone deriva- 

 tives to form derivatives of 7-pyranol. Thus /3-resorcyI- 

 aldehyde and acetophenone condense readily in presence of 

 hydrogen chloride to give 7-hydroxy-2-phenyl-i ; 4-benzo- 

 pyranol hydrochloride. With i-hydrindone, 7-hydroxy- 

 2 : 3-indeno-i : 4-benzopyranol hydrochloride is formed. 

 S-Resorcylaldehyde and 5 : 6-dimethoxy-i-hydrindone are 

 condensed by hydrogen chloride in methyl-alcoholic solu- 

 tion to give 7-hydroxy-5 : 6-dimethoxy-2 : 3-indeno-i : 4- 

 benzopvranol hydrochloride. The substances thus produced 

 may also be obtained by the action of alcoholic hydrochloric 

 acid on the o-hydroxybenzylidene-i-hydrindones, and, con- 

 versely, the latter are again produced from the pyranols by 

 the action of alcoholic potash. — .Arsenic di-oxide : J. T. 

 Hewitt and T. F. Winmill. The authors have examined 

 Bamberger and Philipp's arsenic di-iodide, and find that 

 it has the formula As,I,. Pyridine decomposes it immedi- 

 ately, liberating arsenic. — The formation and reactions of 

 imino-compounds, part iv. , the formation of 1:4- 

 naphthylenediamine from ethyl 7-imino-a-cyano-7-phenyl- 

 butyrate : J. F. Thorpe. — Mercury derivatives of pseudo- 

 acids containing the group .CO.NH. : S. J. M. Auld. 

 Unlike cyanuric acid, which forms two isomeric mercuric 

 salts, all the pseudo-acids containing the group .CO.NH. 

 examined have given only one derivative, in all cases an 

 N-salt containing the group .CO.Nhg. — The influence of 

 substitution in the nucleus on the rate of oxidation of the 

 side-chain, iii., oxidation of the nitro- and chloronitro- 

 derivatives of toluene : J. B. Cohen and H. J. Kodsman. 

 — The reducibility of magnesia by carbon. Preliminary 

 note : R. E. Slade. The two methods, which furnished 

 a positive result, confirm the experiments of Lebeau, but 

 whereas this author considt-rs that the reduction onlv occurs 

 at or above the boiling point of magnesia when the vapours 

 come in contact, the present research seems to show that 

 the reaction can take place at temperatures below the 

 melting point of this oxide. — The reaction between organo- 

 magnesium halides and nitro-compounds. Preliminary 

 note : R. H. Pickard and J. Kenyon. .'\romatic 'nitro- 

 compounds react verv vigorously with an organo-magnesium 

 halide in ethereal solution. — .\ method for the determination 

 of the equilibrium in aqueous solutions of amines, pseudo- 

 acids and bases and lactones : T. S. Moore. — The " true " 

 " ionisation constants " and the " hydration constants " of 

 piperidine, ammonia, and triethylamlne : T. S. Moore. 



Institution of Minins^ and Metallurgy, May 16. — Prof. 

 William Gowland, president, in the chair. — .Siberian mines 

 and mining conditions : .\. L. Simon, A description of the 

 mines and mining conditions more particularly in the 

 province of Tomsk, the Ural and Orenburg districts, and 

 the Kirghese Steppe. Beginning with a brief historical 

 note, the paper dealt with climate, travelling conditions, 

 the Russian system of weights and measures, mining laws 

 and administration, the methods adopted in applying for 

 claims, prospecting, opening out and working iron, copper 

 and gold mines in Siberia, with details of costs and labour 

 conditions. — Notes on a modern stamp mill : Gilmour E. 

 Broiwn. \ series of notes on various details of two stamp 



NO. 1962, VOL. 76] 



mills, compiled from personal experience and observation, 

 containing figures relative to. wear, cost of renewal, and 

 the general efliciency of different component parts of the 

 installation. — The use of zinc in assaying copper matte, 

 &c. : Donald M. Levy. A description of results obtained 

 by the employment of zinc for separating copper from the 

 solution when assaying mattes, the copper and iron con- 

 tents of which were both to be determined. The method 

 described involves the use of only one reagent for the two 

 operations. Figures were given erf a series of comparative 

 experiments showing the success of the method in practice. 

 — A method of leaching gold ore tailings : R. S. Botsford. 

 \ brief note showing how, by slow and careful upward 

 leaching, and continuous drawing off from below with the 

 addition of fresh solution above the ore, a material saving 

 was effected in the time occupied by the leaching process. 



Paris. 

 Academy of Sciepc^s. Mav ^^.—\^. Hmi Becqn-iel in 

 the chair. — The suspended collimator of M. Schwarz- 

 schild : G. Lippmann, The arrangement described by the 

 author in a recent number of the Comptes rendiis was 

 anticipated by M. Schwartzschild in 1904. — The flora and 

 the relative levels of the coal borings of Meurthe-et- 

 Moselle : R. Zeilier. More than 10,000 specimens of 

 fossil imprints of plants have been obtained from these 

 trial borings. Those represent 145 species, some of which 

 are new, and 01 which a detailed account is given. — The 

 positions of the datum stars concerning the planet Eros 

 deduced from the Toulouse negatives : B. Baillaud. .An 

 examination of the causes of the differences between the 

 results of the reduction already published and those 

 otitained from the same plates by Mr. Hinks. — The absence 

 of polarisation of the prominences ; P. Saiet. Light 

 from the edges of the sun and of the promiiiences is 

 not polarised, and hence there is a contradiction between 

 the theories of Schmidt and Julius and Fresnel's theory 

 of polarisation. — .Applications of a theorem of approximate 

 convergence : Ernst Fischer. — The viscosity of fluids : 

 Marcel Briliouin. A tentative formula for the viscosity 

 of fluids is given and applied to the case of carbon dioxide, 

 the viscosity of which has been studied experimentally 

 both in the liquid and gaseous states. — A new property 

 of gases issuing from flames : Maurice de Broglie. The 

 gases from flames contain centres electrically neuter, 

 possessing the properties of taking a charge under the 

 influence of the radium radiation or Rdntgen rays, and of 

 being arrested by an ordinary cotton-wool filter and 

 destroyed by heat. Gases containing these centres, after 

 washing in dilute saline solutions, acquire a higher ionisa- 

 tion. — The sensibility of the electrostatic telephone: Henri 

 Abraham. — Measurements of wave-lengths in the iron 

 spectrum for the establishment of a system of spectro- 

 scopic standards : H. Buisson and Ch. Fabry. A com- 

 pletion of results already published by measurements in 

 the ultra-violet. — Some double sulphites of hypovanadic 

 acid : Gustave Gain. The alkaline bases possess the 

 property of combining easily with hypovanadic acid in 

 presence of sulphurous acid, giving well-defined double 

 sulphites. Details are given of the compounds obtained 

 with potassium, ammonium, rubidium, caesium, thallium, 

 sodium, and lithium. — Lead selenide : H. Peiabon. A 

 study of the fusibility curves of mixtures of selenium and 

 lead. — The methvl ethers of allyl and propargyl carbinols : 

 M. Lespieau. A study of the action of allyl bromide 

 and monochlormethyl ether on magnesium. The result- 

 ing mixture of di-allyl and the ether 



CH,=CH— CH,— CH,.O.CH, 

 could not be separated by fractional distillation, but the 

 separation was easily effected after converting into the 

 bromine addition products. — A new crystallised principle 

 from kola : M. Goris. Hitherto only two definite com- 

 pounds, caffeine and theobromine, have been isolated fron 

 kola ; the author describes a method of treatment by 

 means of which a third substance can be obtained, kola- 

 tine, a phenolic substance of the formula C,H,|,0,. — The 

 ferment of the fig (Ficiis carica) : A. Briot. The coagula- 

 tion of fresh milk by extract of fig is retarded or prevented 

 by the existence in the milk of an antiferment. Heat 

 destroys this antiferment, and hence boiled milk is mov 



