March 31, 1898] 



NATURE 



509 



between the different sections and individual papers, the 

 unity of the whole would have been such as to make the 

 four volumes of the Arbeiien an excellent special treatise 

 on physical chemistry. 



Although this would undoubtedly have increased the 

 value of the work to outsiders, it is perhaps rather an- 

 tagonistic to its raison d^etre, since it is primarily the 

 collected published papers from the physico-chemical 

 laboratory of the University of Leipzig. As such it is not 

 only a welcome souvenir to those who have worked in the 

 old laboratory, but it should be in the hands of all who are 

 interested in physical chemistry. John Shiei.ds. 



OUR BOOK SHELF. 



Archives of the Roentgen Ray. Vol. ii. No. 2. Radio- 

 graphy in Marine Zoology, being a Supplement to 

 the Archives of the Roentgen Ray. The British 

 Echinodermata. By R. Norris Wolfenden, M.D. 

 Cantab. (London : The Rebman Publishing Com- 

 pany, 1897.) 



To deal with the above-named publications in inverse 

 order, it may be remarked that Dr. Wolfenden's treatise 

 of fifteen quarto plates and six pages of letterpress 

 is the outcome of the radiography, by means of a 

 lo-inch spark-coil, of a collection of Echinodermata 

 dredged in the Orkney Seas during 1896-97. The 

 author claims that it has been his endeavour "to show 

 that the new method of radiography may be made of 

 considerable service in zoology, as an accessory to dis- 

 section and description." The plates are mostly inartistic 

 and of no practical value to the zoologist — at best but 

 poor examples of the radiographer's art. While they 

 betoken a laudable desire on their originator's part to 

 develop the new light of physical science, they partake 

 of the nature of m^te experimental memoranda such as 

 are usually made a basis for fuller investigation and 

 allowed to pass unpublished. 



Of the Archives it may be noted that with the 

 number under review the title is changed from that " of 

 Skiagraphy" to that "of the Roentgen Ray." The 

 seventeen pages before us are chiefly conspicuous as con- 

 taining a full report of the inaugural meeting of the 

 Rontgen Society of London, a combination of a con- 

 versazione, a trade exhibit, and a concert, set around a 

 presidential address. The latter, reported in extenso, 

 deals with the history, development, and application of 

 the Rontgen discovery, to the invoking of Shakespeare. 

 Special stress is laid upon the advantages likely to accrue 

 to the medical profession by the employment of the 

 X-ray tube ; and since the members of that profession 

 seem likely to profit both by its use and its user, they 

 ought for the future to be among its foremost advocates. 

 It is thus but appropriate that the body of the Archives 

 should be devoted to a brief description of five plates 

 mainly illustrative of the osteological phenomena of 

 "acromegaly" — which we would remark is now more 

 correctly known as megalacria. Beyond this there are 

 a few desultory notes of a practical order, but we are 

 unable to detect anything which might not have been 

 communicated in the customary form to one or other of 

 the established scientific societies. We fail to see the 

 justification for the foundation of a new society, and 

 shudder at the assertion that there are already " three 

 journals established for the publication of observations 

 and discoveries connected with the Roentgen rays," not 

 to say at the suggestion of rivalry in the wording of 

 the cover of the issue under review. Concerning the 

 zoological departure, however, a good purpose will have 

 been served, in the awakening of the mind of the 

 physicist to the fact that animals exist and have a form 

 and symmetry capable of scientific treatment. 



NO. 1483, VOL. 57] 



Practical Electricity and Magnetism. By John Hender- 

 son, B.Sc. (Edin.), A.LE.E. Pp. XV -I- 388. (London: 

 Longmans, Green, and Co., 1898.) 



This little volume, the second of a series of laboratory 

 manuals at present being brought out by Mr. Henderson 

 in conjunction with Mr. Joyce, has certainly many points 

 about it which are not only original, but which should 

 also render it of the greatest value in the physical 

 laboratory. 



It is designed " to provide a course of instruction for 

 carrying out a progressive series of experiments in 

 electricity and magnetism," and, though it is written, not 

 for technical students, but for students of science, one is 

 nevertheless struck with the author's extremely high ideal 

 of laboratory experimental work. The student receives 

 at the outset a preliminary admonition which cannot be 

 described as other than most excellent and to the point. 

 He is assumed to have plenty of time at his disposal, and 

 not to be engaged in getting through a certain set of 

 experiments in a given time : conditions which can hardly 

 be expected of students preparing themselves for any 

 practical examination, or even in every case of students 

 engaged in original research. The writer's effort to 

 inculcate an almost impossible ideal is none the less a 

 most praiseworthy feature of the book. 



The descriptions of recent experimental work are well 

 up to date, though perhaps such work has received here 

 and there an almost undue prominence. At the end of 

 each section, a list of references to original papers bear- 

 ing on the subject is given. These lists, which are care- 

 fully prepared, will recommend the book to all who are 

 engaged in looking up in detail any particular branch of 

 the subject. 



The notation used is not always happily chosen, as, for 

 example, the double meaning of the letter R on 

 p. 108-9 ; 3.nd the book is by no means entirely devoid 

 of unfortunate mistakes, as in the table on p. 378, where 

 the mechanical equivalent of heat is given as "42400 

 grms. per ''C " instead of "42400 grm -cms. per °C." 

 Such faults will, however, no doubt disappear in a second 

 edition. 



Much practical and detailed advice on the carrying out 

 of experiments is given, which it would be hard to find in 

 so concise a form elsewhere ; and, though the manual is 

 for this very reason not exactly readable, yet this portion 

 of the work, together with the tables of references to 

 original papers already alluded to, and the concluding 

 set of numerical tables and physical constants, combine 

 to make up a most useful work for the physical laboratory. 



D. K. M. 



La photographic et Petude des nuages. Par Jacques 

 Boyer. 8vo. Pp. vi -I- 80. Twenty-one illustrations. 

 (Paris : C. Mendel, 1898.) 

 At the International Meteorological Conference at 

 Munich, in 1891, a Committee was formed to consider 

 the question of concerted observations on the direction 

 of motion and the height of clouds, and subsequently 

 various countries were invited to undertake special 

 observations during a year commencing May i, 1896, a 

 period which was afterwards extended until August 1897. 

 A Committee was also appointed to prepare a Cloud Atlas, 

 based on the classification of Dr. Hildebrandsson and the 

 late Mr. R. Abercromby, and instructions for observing 

 and measuring the altitudes of the clouds by theodolites 

 and photogrammeters were prepared by experts in this 

 branch of meteorological science. The present handy 

 little volume is the outcome of this action, and brings 

 into a small compass a considerable amount of useful 

 information which is spread over various publications, 

 some of which are not easily accessible. It is divided 

 into four parts : (i) the history of the subject from the 

 middle of the eighteenth century ; (2) classification ac- 

 cording to the atlas above referred to, with a number of 



