32 



SCIENCE. 



[N. S. "Vol. V. No. 105. 



ticularly in the case of contradictory statements 

 on different pages. For instance, on page 87 it is 

 said that the Sonoran family Geomyidw has only 

 two genera (inferentially Oeomys and Thomomys), 

 while on the same page the genus Heteromys is 

 added, and on a later page (366-7) no less than 

 seven genera are enumerated as included within 

 the family ! Again, on page 342 it is stated 

 that nomember of the family Geomyidse is found 

 within the limits of the Holarctic region, while 

 on page 366 we are told that the genus Thomomys 

 of this family ' penetrates into the Canadian 

 sub-region of the Holarctic' 



Lack of personal familiarity with the geo- 

 graphic distribution of living mammals in North 

 America, and carelessness in examining current 

 literature, have led to a number of additional 

 errors. For instance, the genus Spermophilus 

 is said to be restricted to the ' Holarctic ' (= Bo- 

 real circumpolar) region, whereas we have one 

 Tropical and at least a dozen Sonoran species, 

 and two well marked Sonoran sub-genera. 

 Again, the lynxes are said to be ' absolutely 

 confined ' to the Holarctic, while in the United 

 States they range throughout the Sonoran and 

 south into Mexico. Zapus also is said to be 

 ' solely Holarctic, ' although it is common as far 

 south as the city of Washington. In the case 

 of the rabbits it is stated that the greater num- 

 ber of species are Holarctic. In America the 

 contrary is true, the greater number being Aus- 

 tral or Sonoran. We are told that Notiosorex, a 

 genus of shrews, ranges south to Central Amer- 

 ica, but it is unknown from any point south of 

 Mazatlan, in Mexico. Similarly the raccoons 

 (genus Procyon) are said to occur ' over most 

 parts of North and South America, ' but in North 

 America they are absent from the northern half 

 of the contiiient. 



The book is well printed and some of the 

 illustrations are good ; others, as, for instance, 

 that of the tree-shrew (Fig. 61), look as if they 

 might have been exhumed from the tombs of 

 the ancients. 



The work deserves a critical review from the 

 paleontological side by some one competent to 

 speak from the American standpoint. Then a 

 revised and corrected edition should be brought 

 out, for in spite of its imperfections, the book 

 is probably the most useful contribution ever 



made, at least in the English language, to the 

 subject of the distribution of the Mammalia, 

 living and extinct. C. Haet Meeeiam. 



The Elements of Electrochemistry. By Max Lb 



Blanc. Translated by W. R. Whitney. 



Pp. x+284. New York, The Macmillan 



Company. 1896. Price, $1.50. 



This volume is the English version of Le 

 Blanc's Lehrbuch der Elektrochemie, which was 

 published at Leipzig in the early part of this 

 year. 



The original met with a cordial reception, 

 and this translation certainly deserves a warm 

 welcome at the hands of those who are inter- 

 ested in the subject of which this book treats, 

 but who are unable to consult it in the language 

 in which it was written. 



It has been the author's intention, averred in 

 his preface, to ' write as clearly and simply as 

 possible.' In this he has certainly succeeded. 



The opening chapter brings an introduction 

 to the fundamental principles of energy in 

 general, and electricity in particular, which is 

 most logically and lucidly written. 



Next comes a chapter containing a brief but 

 well balanced history of the development of 

 electrochemistry up to the present time, and 

 then follow able presentations of the Arrhenius 

 theory of dissociation, the migration of the ions, 

 the conductivity of electrolytes, electromotive 

 force ; a discussion of galvanic elements and 

 accumulators forms the concluding chapter. 



A careful persual of this treatise will certain- 

 ly place its reader in possession of a clear and 

 comprehensive view of the present state of this 

 important subj ect — electrochemistry. 



Comparison with the original shows the trans- 

 lation to be well done and fluent ; the translator 

 having wisely avoided too close an adherence to 

 the author's style, which at times is a little 

 ponderous. 



Omission, in the English book, of the plus 

 and minus signs, used by Le Blanc to specify 

 the two kinds of ions, is to be regretted. On 

 the other hand, valuable features introduced by 

 the translator are the subject-index and the list 

 of authors' names. 



Feedinand G. Wiechmann. 



Columbia Univkesity. 



