2 "-' 8 >V • i entitle Intelligence. 



to enable persons to become acquainted with the trees in their 

 vicinity without presupposing an extensive knowledge of botany. 

 The characters emphasized therefore are those derived from the 

 leaves and bark rather than from the flowers and fruit. The 

 text-figures include outline drawings of the leaves and half-tone 

 representations of the bark. a. w. e. 



II. Miscellaneous Scientific' Intelligence. 



1. Introduction to Analytic Mechanics ; by Alexander 

 Ziwkt and Peter Field. University of Michigan. Pp. ix, 378; 

 96 figures. New York, 191 2 (The Macmillan Company). — This 

 volume is based to a large extent on Zi wet's Theoretical Mechan- 

 ics, but the Applications to Engineering have been omitted and 

 the analytical treatment has been broadened ; consequently it will 

 be a useful book for a student who is familiar with the founda- 

 tions of mathematics and is well advanced in pure mathematics, 

 but as a text-book for an elementary class it would present diffi- 

 culties. The author obviously takes the German point of view 

 with reference to the subject. While this is doubtless valuable 

 from the theoretical side, the English point of view has been more 

 fruitful in the applications to the numerical solution of problems. 

 One must regard the book to considerable extent as an introduc- 

 tion to theoretical or abstract dynamics rather than the placing of 

 physical problems on a dynamic basis. The real difficulties of the 

 subject are the applications to physical problems, and it is this which 

 should be faced in an elementary course. The greater part of the 

 book is theory. There are not a large number of solved examples, 

 and only a moderate number of exercises for the student to work 

 out. The book is written with care, and while one may not agree 

 with the author's point of view, his own views are logically and 

 consistently carried out. w. b. 



Obituary. 



• Professor Ferdinand Zirkel, the veteran mineralogist and 

 geologist of Leipzig, died on June 11 at the age of 74 years. His 

 work on the microscopic characters of minerals and rocks, pub- 

 lished in 1873, played an important part in the establishment of 

 the new science of Petrography. His other works were numer- 

 ous and include a volume describing the rocks collected by the 

 Clarence King Geological Survey of the 40th Parallel, and several 

 editions of Naumann's Mineralogy. 



Professor Eduard Strassburger, the noted German botanist, 

 died at Bonn on May 19 at the age of sixty-eight years. 



Dr. William McMichael Woodworth, the zoologist, of the 

 Harvard Museum of Comparative Zoology, died recently at the 

 age of forty-eight years. 



M. Lecoq de Boisbeaudran, the emuient French chemist 

 and discoverer of the new element galliu i, died recently at the 

 age of seventy-four years. He was a corresponding member of 

 the French Academy in the section of Chemistry. 



