April 5, 1900] 



NA TURE 



547 



Recent numbers of the Communications from the Physical 



Laboratory of the University of Leyden are occupied with 



_ work carried out in the cryogenic laboratory, which has 



Kbeen reopened after completing certain safety arrangements 



' required by the Privy Council. Dr. H. Kamerlingh Onnes 



ijives an account of certain methods and apparatus, 



including (i) a cryostat or boiling-glass and boiling case, 



for measurements with liquefied gases, especially oxygen ; 



(2) the arrangement of a Brotherhood air compressor for the 

 compression of gases to be kept free from admixture with air ; 



(3) methods of pouring out little quantities of liquid nitrous 

 oxide ; and (4) boiling nitrous oxide in large quantities. In 

 another issue, Dr. E. van Everdingen, jun., describes a con- 

 tinuation of his experiments on the Hall effect at the low 

 temperatures now available, and has found no indication of a 

 maximum value to this effect down to the boiling point of 

 liquid oxygen. Dr. Fritz Hasenoehrl investigates the dielectric 

 constants of liquid nitrous oxide and nitrogen, a branch of 

 investigation previously carried out by Dewar and Fleming. 

 The results are for nitrous oxide i'933, and for oxygen 1*465, 

 as compared with Dewar's f49i, while the Clausius Menotti 

 formula is at any rate not negatived by the experiments. 



Messrs. Watkins and Doncaster have sent us their 

 catalogue of natural history apparatus, books, birds, eggs, 

 lepidoptera and other requisites of the field naturalist. 



A SECOND edition of Part ii. of Prof. Chrystal's "Algebra" 

 has just been published by Messrs. A. and C. Black. The 

 principal changes occur in the sections on the Theory of Series, 

 which have been rendered more useful to students proceeding to 

 study the Theory of Functions. In the interests of the same 

 class of readers, a sketch of the modern theory of irrational 

 quantity has been added to the chapter. The first edition of 

 i'art ii. of Prof. Chrystal's work has already been noticed in 

 Nature (vol. xli. p. 338), and the merits of the work are so 

 well known that it is unnecessary to do more now than announce 

 the publication of th e new edition. 



The London Geological Field Class, conducted by Prof. 

 H. G. Seeley, F.R.S., offers exceptional opportunities of obtaining 

 observational knowledge of the physical geography and geology 

 of the London district. Visits are made to selected places on 

 Saturday afternoons between the end of April and the beginning 

 of July, and short addresses are given upon the characteristics 

 if the rock structures and the development of the land forms 

 -een during the excursions. The places to be visited this year 

 have been selected with the view to illustrate the geological 

 structure of the London basin by an examination of Cretaceous 

 rocks at Godalming, Oxted, Gomshall and elsewhere, and of 

 the Oolite of Bedford. The first excursion will be made on 

 April 28. 



Several parts of elaborate scientific memoirs in course of 

 publication by Mr. W. Engelmann, of Leipzig, have been 

 received from Messrs. Williams and Norgate. Included among 

 these recent works are : — " Monsunia : Beitriige zur Kenntniss 

 der Vegetation des sud- und ostasiatischen Monsungebietes " 

 (Band i.), by O. Warburg; " Monographieen afrikanischer 

 Pflanzen-Familien und Gattungen : IV. Combretaccce excl. 

 Combretum," by A. Engler and L. Diels ; "Genera Siphono- 

 gamarum ad Systema Englerianum Conscripta " (Fasciculus i.), 

 by Drs. C G. de Dalla Torre and H. Harms ; and " Conspectus 

 florae graecae " (Fasciculus i.), by E. de Halacsy. In addition 

 to these publications of the house of Engelmann, we have 

 received from the firm of Gebruder Borntraeger, Berlin, the first 

 part of the first volume of " Die mikroskopische Analyse der 

 Drogenpulver," an atlas for chemists and druggists, by Dr. 

 Ludwig Koch. We propose to review these works when they 

 have been completed. 



NO. 1588, VOL. 61] 



The question as to the origin of the energy possessed by the 

 Becquerel rays is one of consideraole interest. The existence 

 of substances capable of emitting radiations possessing energy, 

 without any appreciable loss of weight or introduction of work 

 from external sources, would appear to be impossible from the 

 view of conservation of energy. The measurements of M. 

 Henri Becquerel upon the deviation of the radium rays in an 

 electric field, taken in conjunction with those of M. and Mme. 

 Curie of the charges carried by these rays, lead to results which 

 show a way out of this difficulty, on account of the extreme 

 minuteness of the quantities of energy in question. The cal- 

 culations of M. Becquerel show that the energy radiated per 

 square centimetre is of the order of one ten-millionth of a watt 

 per second. Hence a loss of weight of about a milligram in a 

 thousand million years would suffice to account for the observed 

 effects, assuming the energy of the radium to be derived from 

 an actual loss of material. 



The detailed study of the hydrocarbon indene has hitherto 

 been hindered by the difficulty of obtaining it in large quantities 

 in a pure state. In the March number of the Journal of the 

 Chemical Society, Messrs. Kipping and Hall describe two new 

 syntheses of indene, in which the yields are practically theo- 

 retical. Cinnamic acid is the starting point, from which 

 o-hydrindone is prepared by methods previously described ; the 

 oxime from this is then reduced to a-hydrindamine, from which 

 indene can be obtained either by heating the hydrochloride at 

 250° C, or by preparing the iodide of trimethyl-hydrindamine 

 and submitting this to dry distillation. The indene thus prepared 

 was shown to be identical with that synthesised by Perkin and 

 Revay, and also with indene from coal-tar. 



It is now very generally agreed that the true constitution of 

 the sulphites is represented by the un symmetrical formula 

 R.SOgOR, as opposed to the symmetrical SO.(OR)2. One 

 interesting outcome of the former view is that there should be 

 isomeric double sulphites, the one R.SOj.OR', and the other 

 R'.S0.2.0R, and Schwicker and Barth have indicated the 

 existence of such isomers in the case of sodium potassium 

 sulphite. Dr. Fraps, however, in the March number of the 

 American Chemical Journal, after carefully repeating these 

 experiments, has been driven to the conclusion that no such 

 isomerism exists in this case. This coincides with the views of 

 Hantzsch, who holds that structural isomerism is unknown in 

 inorganic bodies. 



The additions to the Zoological Society's Gardens during the 

 past week include a Secretary Vulture {Serpentarius reptili- 

 vorus) from South Africa, presented by Mr. James D. Logan, 

 jun. ; a Spanish Blue y[.z.^^\^ {Cyanopolius cooki) IxQva. Spain, 

 presented by Mr. E. G. B. Meade-Wa Ido ; a Greater Black- 

 backed Gull {Larus marinus), European, presented by Mr. H. 

 Clinton Baker ; four Marbled Newts (Molge marviorata) from 

 Bordeaux, presented by Mr. G. A. Boulenger, F.R.S. 



OUR ASTRONOMICAL COLUMN. 



New Variable in Andromeda. — Dr. T. D. Anderson, of 

 Edinburgh, has cornmunicated to the Astronomische Nachrichten 

 (Bd. 152, No. 3632) his observations of the variability of a new 

 variable star in the constellation of Andromeda. The co- 

 ordinates of the star's position are : — 



R.A. = 

 Decl. = 



oh. 

 ■46° 



8-5m 



}(i855- 



lying almost exactly on the boundary between Cassiopeia and 

 Andromeda. It is not mentioned in the Bonn Durchmuslerungy 

 As measured from the comparison stars B.D. -1-46° "38 (8 '5), 40 



