718 



SCIENCE 



[N. S. Vol. XXX. No. 777 



Page 142. The sand box is recommended 

 for playgrounds. I think there is no other 

 single feature that figures in the equipment 

 of a playground that even approaches the sand 

 box in its unhygienic, bacteriological and 

 parasitic possibilities. 



Page 167. Dr. McKenzie advises the use of 

 floor sockets for fixing apparatus like the horse, 

 parallel and horizontal bars on the floor of the 

 exercising hall. It is only fair to state that 

 a number of men have found or judged this 

 device to be less convenient and utilitarian 

 than the old movable apparatus. The experi- 

 ence at Pennsylvania, however, has been satis- 

 factory. 



Page 191. It is stated that summer courses 

 in physical instruction are given at the College 

 of the City of New York. This is a mistake. 



Part II., Exercise in Medicine, contains 

 much that interests the non-medical reader. 

 It is rather too popular and brief for the 

 specialist or general practitioner concerned 

 with the various diseases discussed. It con- 

 tains very little which the "teacher of the 

 youth" would be expected to apply. The 

 average " student and the practitioner of phys- 

 ical training " who has had no medical experi- 

 ence should not attempt the treatment of 

 medical cases unless under the direction of a 

 competent physician. " Eound back and 

 stooped and uneven shoulders " are not neces- 

 sarily medical; but scoliosis and locomotor 

 ataxia are samples of abnormal conditions 

 which the non-medical man would do well to 

 leave alone — unless he has a training and an 

 experience like that of Bolin. 



But I take it Dr. McKenzie has not at- 

 tempted to prepare a text-book for such read- 

 ers, but rather to present a discussion which 

 will show them the relation of exercise to the 

 treatment of various diseases so that they may 

 secure an intelligent sympathy for the logical 

 and common-sense principles which he has 

 brought together. 



In conclusion it may be said that in its 

 " purpose to give a comprehensive view of the 

 space exercise should hold in a complete 

 scheme of education and in the treatment of 

 abnormal or diseased conditions," this book is 

 a success. Thomas A. Storey 



Second Appendix to the Sixth Edition of 

 Dana's System of Mineralogy. By Edward 

 S. Dana and William E. Eord. New York, 

 John Wiley & Sons. 1909. 

 Dana's " System of Mineralogy," as a stand- 

 ard work of reference, has become so in- 

 dispensable to every one interested in minerals 

 that all additions to it, which tend to bring 

 the work up to date, will always be welcomed. 

 Ten years have elapsed since the first appendix 

 appeared and this period has been one of great 

 activity in mineralogical research. Many new 

 mineral names have been proposed, and new 

 occurrences, forms and physical properties of 

 known species have been described. This 

 second appendix contains an excellent bibli- 

 ography of mineralogical literature issued 

 during the ten years with a concise statement 

 of the subject matter of each article and quo- 

 tation of new forms, and complete descrip- 

 tions of all minerals that have been announced 

 as new species ; consequently references to sev- 

 eral hundred minerals are included in the 

 book. Over two hundred new names have been 

 proposed for minerals and from this number 

 the authors have selected about sixty, on ac- 

 count of their better descriptions, as meriting 

 the distinction of being new species. As to 

 this limited selection from so many new com- 

 pounds, some disagreement with the authors 

 may arise, but they feel justified in relegating 

 to subordinate rank most of the so-called new 

 minerals, because of the insufBcient data to 

 establish their recognition as species. 



The appendix is similar in size, binding and 

 arrangement of contents to the first one, issued 

 in 1899. The minerals are arranged in alpha- 

 betical order with all of the new names in 

 heavy-faced type, but in the classified list only 

 those considered as new species are in bold 

 type. The great task of preparing this appen- 

 dix was begun by the senior author and con- 

 tinued by him until 1906 when his health com- 

 pelled him to give up the work, and it devolved 

 upon the junior author to complete the book 

 to the present year, which he has ably done. 



Every scientific investigator will deeply re- 

 gret the loss of Professor Dana from active 

 work, and it is the heart-felt wish of his legion 

 of friends that he may speedily regain his 

 health and strength. With his retirement, and 



