Maech 13, 1896.] 



SCIENCE. 



415 



names which Taylor has explained erroneously 

 we notice Arkansas, Arawak and Tallahassee. 



A. S. G. 



The Sun. By C. A. Young. New and revised 



edition. New York, D. Appleton & Co. 



The revised and slightly enlarged edition of 

 Prof. Young's ' Sim ' will be read by all with 

 great interest. The first edition of this justly 

 popular work appeared in 1881. Since that 

 time many advances have been made in our 

 knowledge of the sun ; new methods of obser- 

 vation have been developed. Prof. Young 

 tried to keep pace with this progress by the ad- 

 dition of notes and appendices in the various 

 editions that have appeared during the interval. 

 He now finds, however, that such expedients 

 are inadequate, and he has, therefore, revised 

 the work and made it representative of the sci- 

 ence of to-day. 



In general form and appearance the book re- 

 mains the same as in the first edition. There 

 are, however, a number of new cuts, and the 

 various subjects, treated of in a single chapter, 

 are more clearly separated. Many ' headlings ' 

 are introduced into the text, thus greatly aiding 

 a clear understanding of the subject-matter. 



Among the most prominent features of the 

 new edition we note the introduction of the 

 latest work on the solar parallax. Gill's 

 methods and results are most carefully treated. 

 Again the great advance in solar spectroscopy 

 is represented by the work of Rowland ; the 

 photography of the prominence by that of Hale ; 

 the identification of helium by Ramsey. The 

 progress made in the spectroscopic study of the 

 sun is most readily brought out by a compari- 

 son of our present knowledge with that of 

 1881. In the first, editions of his work. Prof. 

 Young mentions twenty-one elements as known 

 to exist in the sun. In all of these 860 lines 

 had been identified. Prof. Rowland has now 

 tried sixty elements ; thirty-six of which he 

 finds in the sun ; sixteen he does not find there 

 and the remaining eight are doubtful. Of one 

 element alone, iron, he has identified more than 

 2000 lines ; more than twice as many as were 

 known in all the elements fifteen years ago. 



A careful comparison of the last chapters, the 

 summaries, of the two editions leaves us with 



a feeling of disappointment, of expectation un- 

 fulfilled. Our advance in the knowledge of 

 solar physics has not been so rapid as we fondly 

 imagined. During the last decade and a-half 

 no new great principle, no law, has been dis- 

 covered. We have improved our methods of 

 observation ; we have collected more data ; but 

 we know little more of the actual condition of 

 the sun itself than we did in 1881. The first 

 edition of Professor Young's book ends with a 

 statement of the four most important and fun- 

 damental problems of solar physics which were 

 at that time pressing for solution. Fifteen 

 years have since elapsed and these four prob- 

 lems are still unsolved, are still pressing for 

 solution. 



C. L. P. 



Elements of Modern Chemistry. By Chaeles 



Adolphe Wuetz. Fifth American Edition. 



Revised and enlarged by Wm. H. Greene, 



M. D., and Harry F. Keller, Ph. D. 12 mo. 



Pp. 788. Philadelphia, J. B. Lippincott & 



Co. 1895. 



The appearance of the fifth revised and en- 

 larged edition of the translation of this well- 

 known work may be taken as evidence that 

 many have found it useful. The writer be- 

 lieves, however, that a better elementary treatise 

 might have been made, if the translators had 

 followed less closely the plan of the original. 

 The introduction is clear and satisfactory. In 

 the next twenty-seven pages we find a dis- 

 cussion of the laws of definite and multiple 

 proportions, equivalents, the laws of Gay- 

 Lussac, Ampere and Avogadro, the atomic the- 

 ory, the laws of isomorphism and specific heats, 

 nomenclature ***** oxygen acids, 

 metallic hydroxides, oxygen salts, nomencla- 

 ture of non-oxygenized compounds, alloys and 

 amalgams. The study of hydrogen and the 

 other elements is then begun. It needs no 

 argument to prove that this order of subjects is 

 not elementary. 



The succession of topics in the study of the 

 compounds of carbon is also unsatisfactory. 

 The order is the following : constitution of or- 

 ganic compounds, formation of hydrocarbons 

 ***** monatomic radicals and poly- 

 atomic radicals, including general remarks 



