Decembee 22, 1905.] 



SCIENCE. 



831 



pound denoted by the expression of its com- 

 position by the smallest possible whole num- 

 bers of combining weights of the elements 

 which form it.' The atomic theory is first 

 mentioned on page 341, Avogadro's law on 

 page 352. Considerable prominence is given 

 to energy changes accompanying chemical 

 changes. Many references to and quotations 

 from the writings of Dalton, Davy and others 

 impart an historical flavor to the book. An 

 appendix of fourteen pages treats of the gen- 

 eral characters of the eight groups of elements. 



The author has certainly been successful in 

 not producing ' a catalogue of chemical odds 

 and ends.' Whether the method of treatment 

 is an improvement upon the more common 

 methods is a question that must be decided 

 by trial in the lecture room. 



Noyes's Organic Chemistry. — The author 

 states in his preface that " an attempt is here 

 made to present the fundamental principles of 

 organic chemistry for the use of those begin- 

 ning the subject. The most radical departure 

 from the method of treatment adopted in other 

 books treating of the same subject consists in 

 the dropping of the division into ' fatty ' and 

 ' aromatic ' compounds and in the adoption of 

 what appears to the author a more funda- 

 mental and logical classification." 



The subject-matter is divided into twenty- 

 five chapters. ' Of these, chapters I. and II. 

 deal with purification and analysis of com- 

 pounds, the determination of molecular 

 weights and formulas and a general discussion 

 of the physical properties of organic com- 

 pounds. Chapters III. to VIII., inclusive, 

 treat of the hydrocarbons. In chapter IX. 

 is given the classification of the derivatives 

 of the hydrocarbons. The remaining chap- 

 ters are devoted to a discussion of these 

 derivatives. 



The most striking feature of the book un- 

 doubtedly lies in the fact that the time-hon- 

 ored classification of the compounds into the 

 so-called ' fatty ' and ' aromatic ' classes is set 

 aside and the corresponding members of each 

 class discussed together. While this is a very 

 radical departure, there is no question but that 

 the method chosen is a logical one and at least 

 well worth a trial in the lecture room. The 



book bears unmistakable evidence that its au- 

 thor has been an enthusiastic worker in the 

 field of organic chemistry and that he has 

 given to the student, in so far as the space 

 would permit, a clear and comprehensive dis- 

 cussion of the science as it exists to-day. It 

 is a question whether some of the general re- 

 actions discussed might not have been illus- 

 trated by simpler examples. As the author 

 states in his preface, however, ' no two authors 

 would make the same selection, and that here 

 given is doubtless open to just criticism at 

 some points.' 



To write an elementary text in a science 

 which includes a study of over 100,000 com- 

 pounds besides a number of growing theories 

 is not an easy task, and the person who does 

 this successfully is certainly deserving the 

 commendation of the teachers of the science. 

 Noyes's text must be regarded along with 

 Eemsen's as the best of modern elementary 

 texts of organic chemistry. 



Smith's PraMische is the German transla- 

 tion of his well-known 'Laboratory Outline 

 01 General Chemistry,' which is undoubtedly 

 one of the best of the ' laboratory outlines ' 

 for mature students. 



Smith and Kellar's Experiments has de- 

 servedly reached its fifth edition. The ex- 

 periments are well chosen to illustrate the 

 principles of chemistry. A number of quan- 

 titative experiments are included. 



William McPherson. 



SCIENTIFIC JOURNALS AND ARTICLES. 



The Journal of Experimental Zoology for 

 November, 1905. T. H. Morgan ('Polarity' 

 considered as a phenomenon of gradation of 

 material) discusses in the light of some new 

 experiments with the hydroid Tubularia the 

 so-called ' polarity ' of organisms, as seen espe- 

 cially in the phenomenon of regeneration. 

 The author advances the hypothesis that or- 

 ganic 'polarity' is an expression of the grada- 

 tion of the organ-forming substances present 

 in the adult. These substances are traceable 

 to the egg, which owes its development in 

 part to their localization. The phenomena of 

 development and of regeneration are thus 

 brought under a common point of view. H. S, 



