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THE POPULAR SCIENCE MONTHLY. 



use in differentiating a man from his fel- 

 lows ; and the finger prints are found to 

 afford one of the most certain marks of 

 identification. The question whether pat- 

 terns are transmissible by descent is an- 

 swered affirmatively ; and this leads to the 

 estimation of their use in indicating race 

 and temperament. In the last chapter the 

 right is discussed of the nine fundamentally 

 differing patterns to be considered as differ- 

 ent genera, and of their more characteristic 

 varieties to rank as different genera or spe- 

 cies, as the case may be, with affirmative 

 conclusions. 



Sound and Music. By the Rev. J. A. Zahm. 

 Chicago : A. C. McClurg & Co. Pp. 452. 

 Price, $3.50. 



The author of this work is Professor of 

 Physics in the University of Notre Dame. 

 The main purpose of the book is to give mu- 

 sicians and general readers an exact knowl- 

 edge, based on experiment, of the principles 

 of acoustics, and to present at the same time 

 a brief exposition of the physical basis of 

 musical harmony. The author believes that, 

 in view of the attention now given to theo- 

 retical as well as practical music in European 

 and American conservatories, this present- 

 ment can not be considered altogether un- 

 timely. The treatise is based on the recent 

 and most exact observations of modern phys- 

 icists, most prominent among whom are 

 Helmholtz and Koenig, as well as the works 

 of the older acousticians, and is intended to 

 include a summary of all that has been learned 

 and determined down to the date of publica- 

 tion. To Koenig, the latest of these investi- 

 gators, and the one probably who has carried 

 our knowledge of the philosophy of music to 

 the most successful results yet obtained, per- 

 sonal obligations are acknowledged. The 

 volume has grown out of a com - se of lectures 

 that were given in 1891 in the Catholic Uni- 

 versity of America, Washington, D. C. These, 

 however, have been thoroughly revised, with 

 the purpose of making the exposition of the 

 subject more complete than was possible in 

 lectures actually delivered, so that it is prac- 

 tically a new work. Yet the lecture form has 

 been retained as being more animated and 

 picturesque, and more in keeping with the 

 character of a work that deals so largely with 

 apparatus and experiments. Of the illustra- 



tions and experiments many were prepared 

 expressly for this work, while others are to 

 be found only in the more recent French and 

 German treatises on sound and music. The 

 first chapter, beginning with a reference to 

 the relation of the science to the art of mu- 

 sic, is devoted to the explanation of the Pro- 

 duction and Transmission of Sound and the 

 Nature of Sonorous Vibrations. In the next 

 two chapters the laws of Loudness or In- 

 tensity of Sound and Pitch are considered, 

 with a description of Koenig's Grand Tono- 

 metre Universe!, and the subjects of Telocity, 

 Reflection, and Refraction of Sound. The 

 topics of Musical Strings, Vibrations of Rods, 

 Plates, and Bells, and Sonorous Tubes follow ; 

 after which come the theoretical subjects of 

 Resonance and Interference, Beats and Beat- 

 tones, the Quality of Sound, and Musical In- 

 tervals and Temperament. 



Text-book of the Embryology of Man and 

 Mammals. By Dr. Oscar Hertwig, Pro- 

 fessor Extraordinarius of Anatomy and 

 Comparative Anatomy, Director of the II 

 Anatomical Institute of the University of 

 Berlin. Translated from the third Ger- 

 man edition by Edward L. Mark, Ph. D., 

 Hersey Professor of Anatomy in Harvard 

 University. With 339 Figures in the Text 

 and Two Lithographic Plates. London : 

 Swan, Sonnesehein & Co. New York : 

 Macmillan & Co., 1892. Price, $5.25. 



The fact that this work possessed suffi- 

 cient merit to go through three editions in 

 German in the four years following its first 

 publication, implies an intrinsic merit; for 

 there is no paucity in the literature of this 

 subject, while the new discoveries that are 

 constantly being reported by investigators 

 tend to make a comparatively recent book 

 behind the times, speaking from a scientific 

 standpoint. 



In the first chapter the sexual products 

 are described, and following this is an expla- 

 nation of the phenomena of the maturation of 

 the egg and of the process of fertilization, 

 the author presenting the theory that the 

 female nuclear substance transmits the pe- 

 culiarities of the mother, the male nuclear 

 substance those of the father. This is an 

 expansion of the theory of fertilization into 

 one of transmission. 



We do not think that the translator has 

 been felicitous in his choice in using the 

 term "process of cleavage" for the more 



