584 



NATURE 



[October 3, 1907 



ji The . displacement is real, and is not due to un- 

 r.iiietrical broadening. 



ij) The displacements are different for different lines, 

 (li) The lines of the iron arc can be grouped into series 

 according to the amounts of their displacements. 



(7) Three groups can in this way be distinguished from 

 one another; the displacements of Groups 1., II., III. bear 

 to one another the approximate ratio 1:2:4. (1 he exist- 

 ence of a fourth group is suggested by the behaviour of 

 two lines, but further evidence is needed upon this point ; 

 1:2:4:8 would be the approximate relations existing 

 between the four groups.) 



(8) Though all the lines examined, with two possible 

 exceptions, fall into one or other of these groups, the lines 

 belonging to any one group differ to an appreciable extent 

 among themselves in the amounts of their displacements. 



(cj) The relation between the pressure and the displace- 

 ment is in general a linear one, but some photographs 

 taken at 15, 20, and 25 atmospheres pressure give read- 

 ings incompatible with 'this relation. Other photographs 

 at 15 and 25 atmospheres present values which are com- 

 patible with it. 



(10) The abnormal readings are approximately twice 

 those required by the displacements at other pressures, if 

 the displacement is to be a continuous and linear function 

 of the pressure throughout. 



fii) On the photographs showing abnormal displace- 

 ments the reversals are more numerous and broader than 

 they are on plates giving normal values, and there is some 

 evidence in favour of a connection between the occurrence 

 of abnormal displacements and the tendencv of the lines 

 to reverse. 



Ill, Reversal. 



(i) .As the pressure is increased, reversals at first become 

 more numerous and broader. 



(2) The tendency of the lines to reverse reaches a maxi- 

 mum in the neighbourhood of 20 to 25 atmospheres, and 

 a further increase in pressure reduces their number and 

 width. 



(3) T\yo types of reversal appear on the photographs, 

 symmetrical and unsymmeirical. 



(4) Within the range of pressure investigated, the 

 reversals show no tendency to change their type. 



(5) In the case of unsymmetrically reversed lines in the 

 electric arc, the reversed portion does not in general corre- 

 spond to the most intense part of the emission line, being 

 usually on its more refrangible side. 



(6) The displacements of the reversed parts of the un- 

 symmetrically reversed lines of Group III. are about one- 

 half the displacements of the corresponding emission lines. 

 Indeed, the reversed parts of the lines of Group III. fall 

 apnroximately in Group II. 



(7) No relation between the order of reversal and the 

 frequency of vibration, such as exists in the spark, has 

 been observed in the iron arc for the ranges of wave- 

 length and pressure examined. 



I\'. Intcnsily. 



(i) The intensity of the light emitli'd bv the iron arc 

 is, under high pressure, much greater tlian at normal 

 atmospheric pressure. 



(2) Changes in relative intensity of the lines are pro- 

 duced by pressure. Lists of enhanced and weakened lines 

 are given. 



Paris. 



Academvof Sciences, September 23.— M. Henri Becquerel 

 in the chair. — The red disease of the pines in the Upper 

 Jiuii: E. L. Bouvier. This disease attacks Abies 

 pcciinata and leaves Picea untouched, and during the last 

 year has assumed alarming proportions in the Jura. A 

 fungus would appear to be the cause of the disease, and 

 a'! this attacks pines only, it is proposed as a remedi.il 

 measure to plant no more pines, but to replace them with 

 Picea. Trees that are .tttacked should be cut down, since 

 their vitality is already destroyed. — Parthenogenesis with- 

 out o.>;ygen. The elevation of the parthenogenetic larvre 

 of .\steria up to the perfect form : Yves Delate. The 

 author has repeated the experiments of Loeb on the in- 

 fluence of the absence of oxvgen, but cannot confirm them ; 

 oxygen does not appear to have the influence accorded lo 

 it by I.oeb. The preparation of the solution for the 



NO. 1979, VOL. 76] 



development experiments has been simplified, and now 

 consists of 300 c.c. of sea water, 700 c.e. of a solution 

 containing 388 grams of saccharose per litre, 0-15 gram 

 of tannin dissolved in a little water, and 3 c.c. of a normal 

 solution of ammonia. The eggs, extracted from the 

 ovary, are placed for one hour in 50 c.c. of this solution, 

 then placed in sea water, two or three times renewed by 

 decantation in order lo remove all traces of the reagent. 

 After eighteen hours the vessel swarms with living larva'. 

 Details are given of all the sea-urchins which have reached 

 the fully developed stage, including one abnormal speci- 

 men possessing hexameral symmetry. — The series of 

 methylation of ethyl alcohol from the point of view of the 

 aptitude of isomerisalion of the haloid esters : Louis 

 Henry. The change of an alkyl halidc into an isomer 

 usually means the transference of the halogen atom to a 

 carbon atom combined with a smaller number of hydrogen 

 atoms than the original carbon atom. — The Daniel (1907) 

 comet and its spectrum: Henri Chretien. — Special iron 

 castings, and more especially castings containing nickel : 

 I.(?on Guillet. The net result of this, together with the 

 previous work on the same subject, is that elements such 

 as nickel, aluminium, and silicon, which dissolve in the 

 iron, favour the formation of graphite. Elements which 

 form a double carbide with cementite oppose the form- 

 ation of graphite (manganese, chromium). — Experimental 

 researches on the lesions following compression and crush- 

 ing of the sensitive ganglia : G. Marinesco and J. 

 Minea. — Memory in Convoluta roseoffeiisis : Louis 

 Martin. Specimens of Convoluta removecl from the sea- 

 shore and placed in a jar in the laboratory oscillate for a 

 certain time in synchronism with the time of the tides. 

 Under certain conditions, which are described in detail, 

 this memory disappears. — Contribution to the study of the 

 lower valley of the river Ain : J. B. Martin, 



CONTENTS. PAGF. 



Problems of Ancestry 561 



The Commercial Use of Peat 562 



Books on Wireless Telegraphy. By Maurice 



Solomon 563 



Our Book Shelf: — 



Benjamin: " Machine Design " 564 



Temple; " Flowers and Trees of Palestine" .... 564 



Dalgliesh : " Familiar Indian Birds" — R. L 564 



Calcar : " Progressus Rei Botanica.." Vol. i., part iii. 564 

 Letters to the Editor: — 



Science and Government. — Sir. W. T. Tbiselton- 



Dyer, K.C.M.G., F.R.S. ; A. T. S 565 



The Interpretation of Mendelian Phenomena. — 



Dr. G. Archdall Reid 566 



On Correlation and the Methods of Modern Statistics. 



(///K.t/ra/(vr'.)— Arthur R. Hirks 566 



The Relation of Man to the Animal World.— Sir 



Samuel Wilks, Bart., F.R.S 56S 



Meteoric Shower, from near /3 Auriga?. — W. F. 



Denning 56S 



A New Stratigraphical Fact in the Thames Basin. — 



Rev. Dr. A. Irving 568 



Bees' Stings and Rheumatism. — Dr. E. W. Ainley 



Walker . . 568 



The Country Child in Education.— H. J. Glover . . 568 

 The Centenary of the Geological Society of London. 



By H. B. W 569 



The Fourteenth International Congress of Hygiene 



and Demography 570 



The Hard and Soft States in Ductile Metals. 



(///iislra/ed.) 572 



October Meteors. By W. F. Denning 574 



Mr. Haldane on Scif nee in Commerce 574 



The Rev. Dr. John Kerr, F.R.S. By C. G. K. . . . 575 



Notes. (Il/lis/ra/e,i.) 576 



Our Astronomical Column : — 



New Elements and Ephemeris for Comet \yaTd . . . 580 



September Meteors 580 



The Electric Action of the Sun and of the Moon . . 580 



Perth Catalogue of Standard Stars 581 



Vienna Meeting of the Iron and Steel Institute . . 581 



University and Educational Intelligence .... 582 



Societies and Academies 583 



