420 



THE POPULAR SCIENCE MONTHLY. 



the several processes. Quantities are given 

 in English measures, followed by metric 

 equivalents. In the part devoted to analy- 

 sis are included blow-pipe tests and deter- 

 minations of specific gravity. Several new 

 examples of quantitative separation have 

 been added in this edition, and volumetric 

 analysis has been given a separate chapter. 

 Ninety cuts illustrate the operations de- 

 scribed. A dozen pages of technical infor- 

 mation in regard to reagents are given, also 

 tables of weights and measures, reactions, 

 and solubilities, lists of salts for blow-pipe 

 examination, etc. The uncut edges of the 

 volume are rather inconsistent with the title, 

 " Practical Chemistry." 



The Fallacy of the Present Theory of 

 Sound. By Henry A. Mott, Ph. D, 

 New York (printed for the author): 

 John Wiley & Sons. Pp. 103. Price, 50 

 cents. 



We are informed on page 7 of this book 

 that "in 1877 Dr. II. Wilford Hall pub- 

 lished a work on the ' Evolution of Sound,' 

 in which he carefully considered, step by 

 step, the present undulatory theory of 

 sound, as elucidated by the distinguished 

 authorities." It is furthermore said that 

 Dr. Hall has shown that the current 

 acoustical theory contains numerous fal- 

 lacies, and, from the language adopted 

 throughout the book, we should infer that 

 it is shown to be childish, absurd, and 

 wholly unworthy of credence. Dr. Mott 

 avows his agreement with Dr. Hall, and he 

 gave a lecture before the New York Acad- 

 emy of Sciences, December 8, 1884, stating 

 Dr. Hall's objections to the present theory 

 of sound, and this lecture constitutes the 

 volume before us. Dr. Mott says that the 

 work of exploding this theory has already 

 been pretty well accomplished, and in his 

 preface he gives the names of divers presi- 

 dents of colleges, and professors thereof, 

 from California to New Hampshire and 

 South America, who have accepted " Dr. 

 Hall's discovery," and abandoned as base- 

 less and worthless the hitherto accepted 

 wave theory of sound. 



We can not here state Dr. Hall's case 

 as re-expounded by Dr. Mott, but discharge 

 our duty by informing all who are con- 

 cerned about it where they can get instruc- 

 tion upon the subject. Nor have we formed 



any opinion, from having examined the ar- 

 guments, whether the wave theory of sound 

 has been exploded or not. There is getting 

 to be such a free use of dynamite in these 

 latter days among the supposed fundament- 

 als and essentials of science, and long-es- 

 tablished opinions seem so liable to sudden 

 overthrow, that we are losing our interest in 

 the operations. Perhaps the safest rule to 

 follow in these revolutionary circumstances 

 is to abide by long-tested principles until 

 given up by those longest and most pro- 

 foundly trained in the work of scientific in- 

 vestigation. 



School Bulletin Year-Book of the State 

 of New York, for 1885. By C. W. Bar- 

 deen. Syracuse, N. Y. : C. W. Bardecn. 

 Pp. 160. 



The " Year-Book " is intended to serve 

 as a convenient educational directory for 

 the State of New York. It contains sketch- 

 es of the county superintendents and county 

 commissioners, and a list of the principals 

 of village schools and academies arranged by 

 counties. Every alternate leaf is left blank, 

 for the insertion of notes, additions, and 

 corrections. 



Obiter Dicta. New York : Charles Scrib- 



ner's Sons. Pp. 232. 



This is a collection of essays, which may 

 be called critical or discursive, according to 

 the mood of the reader, on " Carlyle," " Mr. 

 Browning's Poetry," " Truth - Hunting," 

 " Actors," " A Rogue's Memoirs," " The Via 

 Media," and " Falstaff." They embody the 

 " gratuitous opinions " of one who seems to 

 be an independent thinker, forcibly and 

 often very pungently expressed. Each es- 

 say has its own quality; that on "Falstaff" 

 is a fund of humor; and they are all pleas- 

 ant reading. 



The Sun and his Phenomena. By the Rev. 



T. W. Webb. New York: industrial 



Publication Company. Pp. 80. Price, 



40 cents. 



Notwithstanding the multiplicity of 

 popular treatises on astronomy, the author 

 has thought there might still be room for a 

 description of the sun, which, confining it- 

 self to a brief but careful enumeration of 

 its phenomena, may be found serviceable 

 in elementary instruction. The most re- 

 cent discoveries are taken notice of. 



