July 14, 1898] 



NA TURE 



245 



plane. The hyper-elliptic integrals of this more general 

 problem are interpreted in a similar way to the elliptic 

 integrals of the previous discussion. From the nature of 

 the case, in these lectures, an outline sketch of a large 

 subject is all that can be given, but the lines are traced 

 by the hand of a master ; and for filling in the details we 

 must look to the author's treatise, " Ueber die Theorie 

 des Kreisels," which is now in course of publication by 

 Teubner. 



Williavt Stokes, his Life and Work (1804- 1878). By 

 Sir William Stokes. Masters of Medicine. Pp. 256 ; 

 plate i. (London : T. Fisher Unwin, 1898.) 



The memoir before us is an interestingly written account 

 of a man whom all physicians respect. Stokes was a 

 master of medicine, and the inclusion of his biography 

 in this series shows the wisdom of the editor. The name 

 and work of Stokes are perhaps not as well-known to the 

 modern student of medicine as they ought to be ; this is 

 probably due to the fact that not sufficient time has 

 passed for us to appreciate his work, or rather for us to 

 estimate its great value. He worked and taught at the 

 time when exact methods of physical diagnosis were 

 beginning to be applied by the clinician. Pathological 

 chemistry and bacteriology were practically non-existent, 

 and clinical thermometry was in its infancy. The work of 

 Laennec on the stethoscope had attracted the attention 

 of medical Europe, and opened up the enormous field of 

 the correlation between physical signs and symptoms. 

 It is in this particular field that the work of Stokes was 

 done, and his treatise on the diagnosis and treatment of 

 diseases of the chest still remains a classic. With the 

 exception of Laennec's work, which it considerably ampli- 

 fied, this book must be regarded as one of the most 

 noteworthy upon this subject which had until then been 

 written. 



To turn from his professional to his private life, the 

 letters which are given us in this biography show us 

 Stokes as a cultured Irish gentleman, forming the centre 

 of a wide circle of friends. The biography is carefully 

 written, and will appeal to all those who are interested in 

 that epoch of the history of medicine to which its subject 

 belongs. F. W. T. 



Practical Organic Chemistry. By George George, F.C.S. 



Pp. 94. (London : W. B. Clive.) 

 There is no date on the title-page of this book, but the 

 preface bears the date May 1898. No scientific book 

 should, however, be published without the year of publi- 

 cation being printed upon the title-page. 



The book is intended " for the elementary and advanced 

 examinations of the Science and Art Department." It 

 contains a few experiments on the detection of common 

 elements in organic compounds, on melting and boiling 

 points, organic acids, alcohols, sugars, &c., notes on the 

 methods of examination of mixtures containing organic 

 compounds, and on the preparation of some reagents 

 used in organic analysis. The volume will thus make the 

 student acquainted with the reactions of, and the tests 

 for, common organic bodies. 



Food Supply : a Practical Handbook for the use of 



Colonists and all intending to become Farmers Abroad 



or at Home. By Robert Bruce. With an Appendix on 



Preserved and Concentrated Foods, by C. Ainsworth 



Mitchell, B.A. Pp. xvi -I- 159. (London: Charles 



Griffin and Co., Ltd., 1898.) 



This is the second volume of the "New-Land" Series, 



edited by Prof G. A. J. Cole. It is a concise and soundly 



practical manual of farming in which the fundamental 



principles of successful agriculture, and of the selection 



and management of live-stock, are described. It is only 



paying a compliment to the author to state that the 



book contains the kind of information published by 



NO. 1498, VOL. 58] 



the Department of Agriculture of the United States, 

 and in such official publications as the Agricultural 

 Gazette of New South Wales and the Agricultural 

 fournal of the Cape. As we are at present without 

 a central office for supplying information to British 

 farmers, it is the more necessary that the means of 

 education in the science and practice of agriculture 

 afforded by such books as the one under notice, 

 should be widely known. The volume deals with the 

 fundamental principles of most branches of farming, 

 and will prove of service in any part of the world. The 

 forty-nine half-tone reproductions of photographs of 

 representative animals, illustrating the chief breeds of 

 live-stock, will be of particular interest to farmers. 



Royal Gardetis, Kew. Bulletin of Miscellaneous Infortn- 

 ation, \%<^'j . Pp. 437 -f- 68. (London: H.M. Stationery 

 Office, 1897.) 

 The well-known Kew Bulletins afford the best of evi- 

 dence of the valuable work done at the Royal Gardens 

 in advising upon possible developments of the natural 

 resources of our Colonies and dependencies. Each 

 Bulletin contains a number of plain statements of at- 

 tempts made to introduce new and commercially profit- 

 able plants in suitable districts, of improved methods of 

 cultivation, and of work that men trained at Kew are 

 doing in the various parts of the world to which they 

 have gone from the Royal Gardens. The Bulletins 

 issued in 1897 are collected in the present volume, and 

 together they make a worthy contribution to economic 

 botany. Among the contents is a long list of publica- 

 tions issued from Kew during the years 1841-95. This 

 record of accomplished work is an eloquent testimony 

 of the important part which the Gardens take in botanical 

 research, and in developing the resources of the Empire. 

 Several papers on botanical exploration and enterprise 

 are included, and sixty-three pages are devoted to the 

 report of the Royal Commission appointed to inquire 

 into the condition and prospects of the West India 

 Colonies. 



LETTERS ^ TO THE EDITOR 



[ The Editor does not hold himself responsible for opinions eX' 

 pressed 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.\ 



The Spectrum of Metargon. 



We have delayed in replying to Prof. Schuster's letter in your 

 issue of June 30 in order that we might make further experi- 

 ments on the subject. We have had the kind assistance of Prof. 

 Schuster, who demonstrated to us the close similarity between 

 the group of green lines in the metargon spectrum and the 

 spectrum of the blowpipe flame. We subsequently satisfied our- 

 selves regarding the similarity of the metargon spectrum and the 

 " Swan " spectrum, shown by carbon monoxide in a vacuum 

 tube. At first sight, Prof. Schuster seems justified in attributing 

 that spectrum to the presence of carbon or of one of its com- 

 pounds. Yet we think that careful consideration of the follow- 

 ing facts will necessitate a suspension of judgment : — 



(i) The sample of metargon was mixed with twice its volume 

 of oxygen, and sparked for two hours in presence of caustic soda. 

 This sample, introduced into a vacuum tube after removal of 

 oxygen, still showed the same spectrum. 



(2) A little oxygen was introduced into the gas, and the 

 mixture was then admitted to a vacuum tube. Oxygen lines 

 became visible, but no bands of the so-called " carbonic oxide " 

 spectrum. On removing the oxygen by means of phosphorus, 

 the original spectrum appeared with its customary brilliancy. 



Thinking it possible that the ordinary spark may not have 

 had a sufficiently high temperature to decompose an imaginary 

 stable carbon compound, a jar and spark-gap were introduced, 

 and sparks passed through a mixture of metargon with twice its 

 volume of oxygen, standing over caustic soda, for six hours. No 



