May 27. 1909] 



NA TURE 



567 



The relationship of " vital action " to " physical 

 phenomena " is carefully discussed, for the expres- 

 sions " physical " and " vital " point a contrast con- 

 stantly present to the physiologist's mind, and lead 

 to much confusion. He is apt to regard as physical 

 whatever he can test and measure in his laboratory, 

 but cannot, however, make a model of a living cell 

 or isolate it from the " vital " process which sur- 

 rounds its existence in the living body. The techni- 

 calities of the nervous system are relieved by applied 

 side-issues, often in the form of conversations, which 

 enliven what are apt to be mere dry details. 



The chapters on the special senses which close 

 tlie book are fraught with information useful to 

 physiologists, to musicians, and to teachers of singing 

 and voice production. There is a message in the book 

 to men and women of almost every calling, and every- 

 one will find the text to be a model of writing and 

 of how to convey information in a manner which 

 commends itself to a teacher. 



Scientific writings are, as a rule, mere catalogues 

 of facts, put together in a manner more or less irre- 

 levant. There is no reason for this except the 

 absence of literary ability, a factor which obtains 

 all too widely in medical and scientific writings 

 generally. Huxley's works on scientific subjects, Sir 

 Thomas Watson's on medicine, and Druitt's on 

 surgery are e.xceptions to the rule, but they belong 

 to a past generation, and seem to have left 

 behind them no writers of their literary capacities. 

 Dr. Hill, however, appears to have caught something 

 of their inspiration, and we can only hope that he 

 will deal with other subjects within his ken in a 

 manner similar to that which he has given us in 

 •' The Body at Work." 



OL/ff BOOK SHELF. 

 British and American Customary and Metric Legal 



Measures for Commercial and Technual Purposes. 



(Forming the Measure Section of Part i. of "The 



Mechanical Engineer's Reference Book.") By N. 



Foley. Pp. 25. (London : Crosby Lock wood and 



Son.) Price 7^. 61/. net. 

 The necessity for these tables reminds us what an 

 immense amount of time is wasted by the retention 

 of the barbarous and cumbersome English system of 

 measures. In two nations with more than 100 million 

 people, not a small proportion of the school-time of 

 every child is wasted in learning, and those engaged 

 in industry and commerce in using, a system of 

 measures which could not be less adapted to rapid 

 and easy calculation. Yet we seem little nearer the 

 time when our measures will be decimal and eflicient, 

 even though most of the opposition to the decimal 

 system merits no respect. 



The tables before us are for commercial and in- 

 dustrial use. All ordinary lengths, areas, volumes; 

 weights, &c., in English measure can be converted, 

 with their aid, at a minimum of calculation, to the 

 metric equivalent. The range and arrangement of 

 tlie equivalents have been thoughtfully chosen, and 

 the printing is excellent, so the book lends itself to 

 rapid use, and fits its purpose admirably. 



We have only noted two serious misprints (" Tonne 2 

 = 1 ton, I qr., g lb.," and the equivalent of 3 tonnes); 

 there is also an unimportant slip in the equivalent of 



NO. 2065, VOL. 80] 



15 c.c. in cubic inches on p. 10; in many other places 

 where we have tested the tables they are correct. 

 Page 6 is reprinted on p. 7, and p. 10 on p. 11 with 

 only the decimal point moved, which seems a waste 

 of space. 



In defining the ohm, volt, and ampere, the last 

 is confused with i/io of the electromagnetic C.G.S. 

 unit of current, while each of the former is " defined " 

 in terms of the other and the ampere. The correct 

 definitions, however, are mentioned by the author, but 

 not as such. It would prevent confusion if the larger 

 unit of heat were called in these tables a " kg.- 

 calorie " instead of merely a " calorie." 



It increases considerably the simplicity of the metric 

 system if C.G.S. units are uniformly used in it. 

 It is hoped that the author will help, as he well 

 can, to attain this end by giving wherever possible 

 in future editions of these conversion factors, the 

 C.G.S. equivalent as the metric equivalent. 



The units of pressure used in these tables are the 

 engineer's lb. per square inch or kg. per square cm. 

 Though they are thoroughly bad units, as they vary 

 in magnitude from place to place and lead to con- 

 fusion, they have, however, the advantage of con- 

 ciseness over the physicist's " 760 mm. of mercury at 

 0° C. in latitude 45° C. and at sea-level." The mega- 

 dyne per sq. cm., which is nearly the average baro- 

 metric pressure, deserves to be more generally used. 



T. H. L. 



(1) Leitfadcn der Tierkunde jiir hohere Lehranstalten. 

 By K. Smalian. Erster Teil, pp. iv + 40, price 1.20 

 marks; Zweiter Teil, pp. iii + 41-ioo, price 1.50 

 marks; Dritter Teil, pp. 101-208, price 2 marks. 

 (Leipzig: G. Freytag; Vienna: F. Tempsky, igo8.) 



(2) Baa und Geschichte der Erde. By O. Abel. Pp. 

 viii-|-22o. (Same publishers, 1909.) Price 4^50 

 marks. 



(i) In response, we are told, to a widely expressed wish, 

 the author of the first of these works decided to con- 

 dense and simplify his " Grundzuge der Tierkunde " 

 (reviewed on a previous occasion in N.mure) so as to 

 make a text-book. The result is the " Leitfaden," 

 which is issued in three separate fasciculi, respectively 

 suited (beginning with the last) to the requirements 

 of the fourth, fifth, and six forms. The general plan 

 of the work is to take a series of typical animals, and 

 to make them texts for dissertations on the groups 

 they represent. Despite the fact that some of the 

 text-figures are of a somewhat ancient and obselete 

 type, the work seems well adapted for its purpose. 



We cannot, however, congratulate the author on 

 the coloured plates. In the first part, for instance, 

 we see a fox crawling over a slab of blue limestone 

 or slate on which its red coat stands out so conspicu- 

 ously that the presence of the marauder would be at 

 once detected. In the third part the plate of African 

 animals wherein Grant's bonte-quagga (Equus bur- 

 chelli granti) does duty for the zebra (E. zebra) re- 

 appears in spite of attention having been directed to 

 the error in our notice of the " Grundzuge." 



(2) The appearance of the second of the two works 

 is due to a reform which has been made in science- 

 teaching in the middle schools of Austria. To put 

 such reform in action, a suitable and up-to-date text- 

 book was, of course, a sine qud noii; and Dr. Abel 

 was accordingly entrusted with the compilation of 

 such a work. No better man could have been chosen, 

 as is demonstrated by the volume before us, which is 

 practically all that such a text-book should be. It is 

 not overladen with detail, each of the different 

 sections of the subject receives its proper amount of 

 space, and the illustrations, if not in the highest style, 

 are at all events numerous. The volume commences 



