4o8 



iVA TURE 



[August i6, 1906 



for the experiment proved insufficient to Qlvc a satisfactory 

 cjuantitalive measure of tlie amount of radium in the 

 mmeral. This is indicated by a note of interrogation, 

 in other cases no radium at all was detected. In all prob- 

 ability some traces would have been found if more of the 

 mineral had been taken, but the object was to determine 

 wfiether the mineral made anv important contribution to 

 the total radium in the rock. Thus it was not thought 

 worth while to push the examination of accessory minerals 

 ■such as ilmenite or rutile, which only occur in small pro- 

 portions, very far. The quantities of material taken for 

 these ex^penments are given, so that the quantitative signifi- 

 cance of a negative result may be judged. 



It will be observed that certain of the accessorv minerals 

 I.e. zircon, sphene, perofskite, and apatite, which occur in 

 granite are rich in radium. The hornblende, micas 

 tourmaline, and felspars examined contain much less while 

 m quartz none could be detected. 



Academy of Sciences, July 30.-M. II. Poincarc in the 

 chair. — Ihe ub<;ervatory un Mt. Blanc: M. Janssen. 

 .■\n account of the improvements carried out at the observ- 

 atory dijring the past. year, kt present MM. Millochau 

 and Mefanik are carrying out spectroscopical researches 

 and the observatory will shortlv be visited bv MM. (iuille- 

 mard and Moog for the continuation of biological work 

 commenced last year, and bv Alexi. ll.-,nskv for the con- 

 tinuation of his work in astronomii.il phx m, ^.-^The under- 

 lying principles of direct colour ph -i.i|iln. The direct 



photography of colours based on prisiiuuic dispersion- G 

 Lippmann. The single slit of a spectroscope is replaced 

 h) a scries of slits very close together, formed of fine 

 transparent lines, five to the millimetre. Full experimental 

 details are given.— General remarks on interference photo- 

 graphy in colours : G. Lippmann. The mercurv mirror 

 theoretically, can be replaced by anv other method of pi-,,1 

 ducing interference bands. Practi'callv, the unavoidable 

 defects of construction of the biprism'or Fresnel double 

 mirror would render the use of either of them inapplicable. 

 Jhe interference systems produced bv half-silvered mirrors 

 offer more chances of success.— The results obtained f, r 

 the determination of two instrumental constants which 

 occur in certain meridional observations : M. Renan. The 

 application of the method described in a previous communi- 

 cation to the measurement of the angle between the cross- 

 wires of a meridian circle micrometer has shown that the 

 mutual inclination of the wires is not absolutelv constant, 

 but IS a function of the direction of the optic axis of the 

 telescope. U is shown that this error, although small, can 

 be criminated by the author's method.— Observations of 

 the Finlay comet (iqobd) made with the bent equatorial of 



the Observatory of Lyons : J. Guillaume The area of 



Asiatic Russia and the method emplovod in its determin- 

 ation : J. de Schokalsky.— The combinations of ammonia 

 with aurous chloride, bromide, and iodide : Fernand 

 ^V^l',,^^^ preparation and properties of the compounds 

 y'J^I x"iV ■^"'•^"".' AuBr.2NH„ AuCl.isNH, and 

 .•\uCl.jM-I, are described.— Some reactions of liquid 

 chlorine : V. Thomas and P. Oupuis. A description of 

 the reaction of liquid chlorine with iodine, bromine, 

 sulphur, selenium, arsenic, antimonv, bismuth, and gold. 

 — Ihe alloys of manganese and molvbdenum : "^ M. 

 Arrivant. These alloys have been prepared in two ways, 

 by heating a mixture of the two metals in the form of 

 powder to 1500° C, and bv the action of aluminium 

 powder upon a mixture of the oxides Mn,0, and MoO... 

 .■\ scries of alloys containing from 12 per cent, to 30 per 

 cent, of molybdenum was obtained, all of which were 

 shown to consist of free manganese associated with either 

 Mn„Mo or Mn.Mo. Both the latter compounds were 

 isolated. — The variations of electrical resistance of steels 

 outside the regions of transformation: P. Fournel. — The 

 -estimation of ammonia in water by Xessler's reagent : 

 Albert Buisson. The reaction between ammonia, potash, 

 and mercuric iodide is a reversible one, and hence any 

 estimation of ammonia based on the determination of 

 mercury in the brown precipitate is inexact. — Synthetirallv 

 ■prepared /-idite : Gabriel Bertrand and A. Lanzenberg. 

 —Silver sulphide, selenide, and telluride : H. Pelabon. 

 NO. 1920, VOL. 74] 



Deductions from a study of the melting points of mixtures 

 in varying proportions of silver and sulphur, silver ;.-id 

 selenium, and silver and tellurium. The complete curv.- 

 for the last named can be traced experimentally, and shows 

 ''' o"'*^.?!"^ melting at 345°, and Ag,Te, melting at 

 955 ■— The washing of colloidal precipitates : J 

 Ouclaux. The author holds that the complete washing of 

 a gelatinous precipitate is theoreticallv possible, and that 

 in both gelatinous and colloidal precipitates there is no 

 proportionality between the impuritv removed at each 

 washing and that remaining in the precipitate.— The true 

 nature of the a-glucoproteins of IL Lepierre : J. Gali- 

 mard, L. Lacomme, and A. Morel. The constitution 

 attributed by .M. Lepierre to the nitrogenous products 

 employed by lilm for microbial cultures is inexact.— The 

 amylase and nialtase of the pancreatic juice : MM. Bierry 

 and Giaja.— The mechanism of the valves of certain 

 .-^Vcephaleae during opening and closing, and its morphogenic 

 consequences : F. Marceau — A curative product derived 

 from tuberculinin.', .1 crystallised tuberculous poison : 

 Ij. Baudran. I'uberculinine is a poisonous alkaloid 

 extracted in the proportion of o-ob per cent, to o-io per 

 cent, from tubercle bacilli. This alkaloid, when oxidised 

 under conditions specified with calcium permanganate, 

 yields a substance possessing antitoxic power against the 

 poison of the tubercle bacillus.— .-\ tectonic sketch of 

 France : E. Jourdy. 



GOTTINGEN. 



Royal Society of Sciences.— The Nachrichten (physico- 

 mathematical section), part ii. for 1906, contains the 

 following memoirs communicated to the society : — 



February 17. -Seismic records at Upsala (October, 1004- 

 May, 1Q05) : F. Akerblom. 



March 3. — Outlines of a general theorv of linear integral 

 equations (iv.) : D. Hilbert. 



May 12. — Characters of inorganic colloids (ultramicro- 

 scopic observations) : W. Blitz. 



The Business Notices (part i., 1006) include a report on 

 Ihe Samoa Observatory, and an obituary discourse on the 

 late Baron Ferdinand von Richthofen. 



CONTENTS. PAGE 



Anthropological Ethics ,77 



Joseph Priestley. By J. B. C ^^g 



Spherical Astronomy. By P. H. C. ^70 



Our Book Shelf: — 



HolzmiiUer : "Die neueren Wandlungen der elek- 

 trischen Thenrien einschiesslich der Elektronen- 



theorie zwei Vortrage." — N. R. C -So 



Hight: "The Unity of Will. Studies ' of "aii ^ 



Iriationalist " -Sq 



Gautier : " Diet and Dietetics " 380 



Osborne and Osborne : " German Grammar for 



Science Students" ^5,3 



Letter to the Editor: — 



Colour Phenomena in Ihlrlti^ coerulrnLiis. — George 



Massee ,§0 



The Early History of Spitsbergen. < Il/iis/rntcd.) 



By J. W. G 3S1 



Prof. George Rayet. By W. E. P 3S2 



Notes 382 



Our Astronomical Column :— - 



Comet I gob./ (Finlay) 385 



Planets and Planetary Observations 386 



A New Form of Spectroheliograph 386 



The Relations between Science and Industry . , . 386 

 The British Association 



Section C— Geology.— Opening Address by G. W. 



Lamplugh, F.K.S., President of the Section . 3S7 

 Section D.— Zoology.— Openins; Address by J. J. 

 Lister, M.A., F.R.S., President of the 



Section .^qq 



University and Educational Intelligence 406 



Societies and Academies . . 407 



