March 15, 1906] 



NA TURE 



473 



superseded, they keep large manuscript maps on which 

 the newest details are at once entered, and any specialist 

 can obtain on application a drawn copy of the map of any 

 region, which is naturally quite correct and up to date. 

 \ side-issue, which the author does not consider, is whether 

 pei pie would rush into archives with the same eagerness 

 with which they now rush into print, and whether it might 

 be better if they did not. 



I in great alteration which occurs in the fluorescence 

 spectrum of sodium vapour when the wave-length of the 

 exciting light is changed is the subject of a brief com- 

 munication by Prof. R. W. Wood in No. 4 of the 

 Physikalische Zeitschrift. Three kinds of monochromatic 

 light, having wave-lengths 5085, 4799, and 4676 respectively, 

 and generated by a cadmium arc lamp of the Heraeus type, 

 were employed in the experiments. 



The lecture delivered by Prof. Emil Fischer before the 

 German Chemical Society on January 6, and having for 

 its subject his recent researches on amino-acids, poly- 

 peptides, and the proteids, is published in the current 

 number of the Berichte (No. 3). The lecture covers an 

 extraordinarily wide field, and contains a resume of the 

 experimental results obtained during the past five years 

 by Prof. Fischer and his colleagues. A briefer and more 

 general summary of recent work tending towards the 

 synthesis of proteid material is contributed by Prof. 

 Maillard to the Revue generale des Sciences for 

 February 15. 



In the Proceedings of the American Academy of Arts and 

 Sciences (vol. xli., No. 19) Messrs. Gilbert N. Lewis and 

 Plumer Wheeler have studied the electrical conductivity 

 of solutions of potassium iodide in liquid iodine. Such 

 solutions are found to conduct electricity as well as the 

 best aqueous solutions, but they present certain interesting 

 anomalies. In dilute solution the molecular conductivity 

 increases linearly with the concentration, rising to a maxi- 

 mum and then falling as the concentration increases; the 

 phenomena show a certain analogy with the deviations 

 from Ostwald's dilution law in aqueous solutions. The 

 temperature coefficient of conductivity is, moreover, negative 

 for dilute solutions, but with increasing concentration it 

 passes through zero and becomes positive. 



A1.1 hough several attempts have been made to prepare 

 selenium iron alums of the type 



Fe,(Se0 1 ) 3 ,M : ,SeO.,,24H,0, 

 no compound of this group has yet been obtained. In the 

 February number of the Gazzetta Dr. Cesare Roncagliolo 

 describes the method by which he has succeeded in pre- 

 paring the rubidium and caesium salts, 



Fe ! (Se0. 1 ) 3 ,RbSeO,,24H 2 0, Fe 2 (SeOJ 3 ,CsSe0 1 ,24H 2 0. 

 As anticipated, these salts were found to be isomorphous 

 with the ordinary alums. As the rubidium and caesium 

 salts melt at about 40° C. and 55 C. respectively, it may 

 be inferred by analogy with the other alums that the corre- 

 sponding potassium and sodium alums melt below o° C. 

 If this is the case, an explanation is afforded of the failure 

 hitherto experienced to prepare these salts. 



A SIXPEKNY edition of Lord Avebury's " Beauties of 

 Nature and the Wonders of the World we Live in " has 

 been published by Messrs. Macmillan and Co., Ltd. 



Messrs. Perctvu. Marshall and Co. have published, at 

 3<i. net, a pamphlet by Mr. A. H. Stanley dealing with 

 "Patents to Inventors." A chapter on patent agents is 

 included. 



NO. 189S, VOL. 73] 



Messrs. Archibald Constable and Co., Ltd., have 

 published a second edition of Mr. Bertram Blount's " Prac- 

 tical Electro-chemistry," the first issue of which was re- 

 viewed at length in Nature of April 18, 1901 (vol. lxiii., 

 No. 1042). The present edition has been revised and 

 brought up to date. The revision of the section on organic- 

 electrochemistry has been done with the assistance of Dr. 

 Mollwo Perkin. 



The twenty-first session of the London Geological Field 

 Class, conducted by Prof. H. G. Seeley, F.R.S., will be 

 opened on Saturday. April 28, by an excursion from Nut- 

 field to Redhill, for the observation of parallel escarpments. 

 In addition to the Saturday afternoon excursions, vacation 

 visits extending over two or three days will be made with 

 the view of examining a Tertiary locality in the Hampshire 

 basin, the Cretaceous rocks of north-west Norfolk, Devizes, 

 or Folkestone ; the oolites of Swindon or Cheltenham ; and 

 the primary rocks of Clifton, the Mendip Hills, the Welsh 

 border, or Leicestershire. The secretary of the clas- is Mr. 

 J. W. Jarvis, St. Mark's College, Chelsea, S.W. 



A copy of the report of the Felsted School Scientific 

 Society for the year 1905 has been received. The organ- 

 isation of the members of the society into four sections has 

 now been in working order for two years, and has led to 

 sound collective work, and in some cases originated good 

 individual practical study. Special encouragement is given 

 to the individual efforts of members. Like most similar 

 organisations, this society is greatly in need of funds to 

 supply necessary instruments, specimens, and apparatus to 

 carry out the observations and other work planned by the 

 directors. Men of science could encourage the voluntary 

 study of science in secondary schools by presenting duplicate 

 specimens and unused instruments to school scientific socie- 

 ties. The report shows that a sustained effort is being 

 made at Felsted School to create active interest in the study 

 of science. 



Messrs. Isenthal and Co. have just issued new cata- 

 logues dealing respectively with mercury vapour lamps for 

 all purposes, and with electric heating and cooking appli- 

 ances. The mercury vapour lamps are at present made 

 in three standard lengths of 18 inches, 26 inches, and 

 38 inches, so as to utilise fully the various standard 

 voltages from 100 volts to 250 volts. At present the lamps 

 are available only for direct current, though they are re- 

 commended for use on alternating current in connection 

 with the Grisson rectifier and electrolytic condenser. The 

 catalogue of heating and cooking apparatus is excellently 

 illustrated, and is divided into two sections. The first in- 

 cludes appliances for domestic purposes and use in hotels 

 and clubs, while the second is concerned with technical 

 apparatus for use in factories and laboratories. 



OUR ASTRONOMICAL COLUMN. 



Comet 1905c. — Giacobini's comet (1905c) has now become 

 much fainter, but does not set until some 35 hours after 

 sunset. A further instalment of Herr Wedemeyer's 

 ephemeris is given below : — 



Ephemeris 12/;. M.T. Berlin. 



