August 13, 1903] 



NATURE 



34. 



Geographen-Kalender. In Verbindung mit Dr. 

 Wilhelm Blankenburg, Prof. Paul Langhans, Prof. 

 Paul Lehmann, unci Hugo Wichmann, heraus- 

 gegeben von Dr. Hermann Haack. Erster Jahr- 

 gang, 1903-1904. (Gotha : Justus Perthes, 1903.) 



This is the first issue of what is likely to prove an in- 

 dispensable work of reference to geographers of all 

 nationalities, as it gives in a compact form a mass of 

 information on the yearly progress of geographical 

 science in all its branches, besides containing much 

 information of a statistical kind which will be of use 

 to the general public no less than to the expert. 

 Although, perhaps, as is but natural, the greatest 

 amount of attention is given to German work, the 

 book possesses a decidedly international character, 

 account being taken of the most important work done 

 by geographers throughout the world. A set of 

 general tables, &c., for purposes of reference is 

 followed by sections on the main events of the year 

 with a bearing on political geography, on the progress 

 of exploration, the geographical literature of the year, 

 and so on. 



.A striking feature is the attention paid, in a special 

 section from the pen of the general editor, to the 

 progress of geographical education, though in this, 

 more than any other section, the attention is focused 

 on German work, hardly anything being said as to 

 the steps lately taken in other countries to improve the 

 position of geography in the school and college curri- 

 culum. Thus, when speaking of periodical publica- 

 tions devoted to this object, Dr. Haack makes no 

 mention of the Journal of Geography, published in 

 the United States, or of the Geographical Teacher, the 

 organ of the Geographical Association in this country. 

 From a purely practical point of view, a most useful 

 section is the very complete " Adressbuch," which 

 gives the names and addresses of geographers of all 

 nationalities, with a brief statement of their special 

 lines of study or research. The little book, which is 

 most tastefully got up, concludes with an excellent 

 series of maps illustrating the principal 'geographical 

 events of the past year. 



Biological Laboratory Methods. By P. H. Mell. 

 Ph.D., Director of Alabama Experiment Station, 

 Professor of Geology and Botany, Alabama Poly- 

 technic Institute. Pp. xii + 321; 127 figs. (New 

 York : The Macmillan Company ; London : Mac- 

 millan and Co., Ltd., 1902.) Price 6s. 6d. net. 

 This is a well-conceived and eminently useful book, 

 which within convenient compass and in clear language 

 gives an account of microscope and microtome, 

 staining and mounting methods, photomicrographs, 

 and so on. It begins at the beginning, and expounds 

 with simple accuracy the various instruments and 

 methods of the well-equipped biological laboratory. 

 After describing the microscope and the microtome and 

 their accessories, the author discusses, in successive 

 chapters, fixing, imbedding, staining, mounting, and 

 drawing. Five chapters are devoted to photomicro- 

 graphy, and others follow on bacteriological methods, 

 special methods {e.g. decalcification, injection, macera- 

 tion and polarisation). The book ends with useful 

 formulai and tables, and with an appendix on laboratory 

 furniture. We have tested the book as to various 

 points, and have found it practical and lucid in every 

 case. It is in pant a compilation of hundreds of duly 

 acknowledged useful hints and recipes from workers 

 all over the world, but it also expresses the work of 

 one who has faced detailed difficulties in actual prac- 

 tice and overcome them. We have come across many 

 illustrations of American neatness and ingenuity which 



NO. 1763, VOL. 68] 



were fresh to us, and we confidently recommend the 

 book as a worthy companion to Bolles-Lee's vade 

 niecum and similar works. 



Ijain; or, the Evolution of a Mind. Pp. ix + 207. 



I sola; or, the Disinherited. Pp. xv + 153. By 



Lady Florence Dixie. (London : The Leadenhall 



Press, Ltd.) 



These are youthful productions of a versatile writer, 



whose object is to spread the truth about everything 



at whatever cost. " Ijain " traces the development of 



the mind of an unusually thoughtful child, and 



" Isola " is a drama, the object of which is to secure 



greater freedom and fuller opportunities of work for 



women. 



__ rn 



LETTER 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.] 



Radio-active Gas from Bath Mineral Waters. 



Prof. J. J. Thomson has shown that the air extracted 

 from Cambridge tap-water and from the waters of certain 

 deep-level springs is mixed with a radio-active gas 

 (Nature, vol. Ixviii. p. 90). It appeared of special interest 

 to determine whether such a constituent existed in the hot 

 mineral springs of Bath. Samples of water direct from the 

 King's Bath Spring have been examined at the Blythswood 

 Laboratory, and have been shown to contain a radio-active 

 gas in solution. In the first experiments the gas was ex- 

 pelled from a flask containing a litre and a half of water 

 by boiling under a pressure of about half an atmosphere. 

 The amount of gas obtained after passing through a 

 number of drying tubes was small, as was shown by the 

 fact that the pressure only altered by a few centimetres. 

 Yet this was sufficient to produce a marked increase in the 

 lonisation in the testing vessel. The gas was also extracted 

 from the water by exhausting the testing vessel and allow- 

 ing a current of air to bubble through the water and a 

 series of drying tubes into the vessel. In this case the 

 ionisation current increased from four to five times. 



Whichever method was employed for introducing the gas 

 into the testing vessel, it was found that the effect did not 

 assume its full value instantaneously, but gradually in- 

 creased to a maximum and then diminished. The activity 

 reached a maximum in rather more than one hour after 

 the admission of the gas. About half an hour later the 

 activity had diminished to one-half the maximum value. 

 Rutherford {Phil. Mag., v. p. 448, 1903) has observed a 

 similar effect when the emanation from radium is introduced 

 into a closed space. In this case the maximum activity is 

 reached after five or six hours, and the activity decays to 

 half value in 3-71 days. The gas from the Cambridge water 

 lost from 5 to 10 per cent, of its activity in twenty-four 

 hours. The gas from the Bath water appears to be inter- 

 mediate in character between the radium emanation and 

 the Cambridge gas on the one hand, and the thorium 

 emanation on the other. The activity of the thorium eman- 

 ation diminishes to one-half in one minute. 



If the therapeutic action of the Bath waters is due in 

 any degree to the radio-activity of the gases contained in 

 them, the fact that the activity of the gas now being 

 investigated begins to decrease so soon after the gas has 

 been liberated acquires special significance. The opinion 

 is commonly held that the waters of various spas possess 

 greater efficacy when used on the spot. It is probable that 

 this opinion, though doubtless fostered by interested 

 individuals, has some basis in fact, and it is possible that 

 the underlying fact may here find an explanation. 



Prof. Dewar has shown that the Bath waters contain 

 helium. The presence of a radio-active and of an inert gas 

 in the same water is of interest from the point of view of 

 the possible transmutation of such elements. 



Blvthswood Laboratorv, Renfrew. H. S. .\llen. 



