February 13, 19 13] 



NATURE 



645 



The Botany of Iceland. Edited by Dr. L. Kolderup 

 Rosenvinge and Dr. Eug. Warming. Part i. 

 " The Marine Algal Veg'etation. " By Dr. Helgi 

 Jonsson. Pp. vi+i86. (Copenhagen: J. 

 Frimodt; London: John Wheldon and Co., 

 1912.) 

 Danish botanists are to be congratulated on the 

 vigorous manner in which they attack the botany 

 of the various dependencies of their kingdom. In 

 the "Botany of the Faeroes" (1901-1908) the 

 results of a systematic investigation of the flora 

 and vegetation of those islands were presented, 

 and with the completion of that work a similar 

 survey of the botany of Iceland has been com- 

 menced. 



The first part of the Iceland series, namely, the 

 marine alga?, by Helgi Jonsson, has now appeared. 

 It begins with the systematic list, which is con- 

 cisely dealt with. An interesting account of the 

 phytogeographic components of the flora follows, 

 together with a comparison of the floristic features 

 of neighbouring areas. The remaining pages are 

 occupied with a detailed description of the algal 

 communities, and notes on the biology of the 

 species. .\ new method of classification is 

 employed; three main vertical "zones " are recog- 

 nised, and the communities of the littoral zone are 

 subdivided according to their illumination require- 

 ments. It is open to question whether these 

 divisions will meet with general approval, but all 

 will agree that Dr. J6nsson has furnished a most 

 valuable contribution to algological literature. 



A. D. C. 



A Medical and Surgical Help for Shipmasters and 



Officers in the Merchant Navy ; including First 



Aid to the Injured. By W. Johnson Smith. 



Revised by Dr. Arnold Chaplin. Fourth edition, 



revised. Pp. xviii-^355. (London: Charles 



Griflfin and Co., Ltd., 1912.) Price 55. net. 



Dr. Chaplin has re-written the portions of the 



work dealing with the causation of diseases, so 



as to incorporate the recent advances in our 



knowledge, especially of tropical diseases. The 



new scales of drugs and medical and surgical 



appliances, issued by the Board of Trade in 



January, 1912, have been included, and in other 



ways the volume has been brought into line with 



present-day requirements. 



.1 Handbook of Wireless Telegraphy : its Theory 

 and Practice. By Dr. J. Erskine-Murray. Pp. 

 xvi-l-442. Fourth edition. (London: Crosby 

 Lockwood and Son, 1913.) Price los. 6d. net. 

 A REVIEW of the third edition of Dr. Erskine- 

 Murray's book will be found in the issue of 

 Nature for August 24, 1911 (vol. Ixxxvii., p. 240). 

 The additions to the present edition include a new 

 chapter on the telegraphic efficiency of a wireless 

 system ; a theory of abnormal ranges, by night 

 and by day, deduced directly from telegraphic 

 observations, now included in the chapter on 

 transmission ; and new sections in other chapters 

 on the Poulsen, Goldschmidt, and new Telefunken 

 systems. 



NO. 2259, VOL. 90] 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



On the Appearance of Helium and Neon in Vacuum 

 Tubes. 



At the last meeting of the Chemical Society, Sir 

 William Ramsay, Prof. Collie, and Mr. Patterson 

 described some experiments which they regard as 

 proving the transmutation of other elements into 

 helium and neon. I have been making experiments 

 of a somewhat similar character for some time, and 

 though the investigation is not yet finished, the results 

 I have obtained up to the present time seem to me in 

 favour of a different explanation from that put for- 

 ward at the Chemical Society. I described some of 

 these experiments in a lecture at the Royal Institution 

 on January 17, but as the separate copies of that 

 lecture have not yet been issued, I will give here an 

 account of some of the experiments which seem to me 

 to have the most direct bearing on the phenomenon 

 in question. 



I used the method of positive rays to detect the 

 gases ; this method is more sensitive than spectrum 

 analysis, and furnishes much more definite informa- 

 tion. I may say that the primary object of my ex- 

 periments was to investigate the origin and properties 

 of a new gas of atomic weight 3, which I shall 

 call X,, which I discovered by the positive-ray method. 

 This gas, as well as one with an atomic weight 20 

 (neon?), has appeared sporadically on the photographs 

 taken in the course of the last two years ; the dis- 

 charge in the tube being the ordinary discharge pro- 

 duced by an induction coil through a large bulb 

 furnished with aluminium terminals, and containing 

 gas at a very low pressure. There seems to be no 

 obvious connection between the appearance of either 

 of these lines and the nature of the gas used to fill 

 the tube ; the 3 line has appeared when the bulb was 

 filled with hydrogen, with nitrogen, with air, with 

 helium, or with mixtures of hydrogen and oxygen in 

 various proportions; the 20 line when the bulb con- 

 tained livdroEjen, nitrogen, air, hydrochloric acid gas, 

 mixtures of hydrogen and oxygen. 



The experiments I made had for their object the 

 discovery of the circumstances which favour the pro- 

 duction of X., and to test whether it was triatomic 

 hydrogen produced by the discharge, as this is the 

 alternative to its being a new element. I have found 

 that the conditions which lead to a considerable pro- 

 duction of X, generally give rise to the appearance of 

 helium and neon. Indeed, in the great majorit)' of 

 cases in which I have observed the appearance of traces 

 of helium and neon these gases have been accompanied 

 by larger quantities of X, ; this gas seems to have 

 escaped the notice of the readers of the paper at the 

 Chemical Society. I may mention, too, that along 

 with neon of atomic weight 20 there is a line in 

 these circumstances corresponding: to an atomic 

 wei.srht 10 or thereabouts. Though this is probably due 

 to neon with two charges of electricity, it is generally 

 brigfhter in comparison with the neon line than is 

 usual for the lines corresponding- to doublv and singly 

 charged atoms, so that it is not impossible, though 

 perhaps unlikely, that it may be due to a new gas. 



The positive rnvs for the analysis of the gases were 

 produced in a v-essel containing gases at a low pres- 

 sure. I shall call this the testing vessel ; the vessel 

 in which the various processes for generating X, 



