September 27, 1895.] 



SCIENCE. 



417 



account of Clairaut's treatise on the figure of 

 the earth, we learn that ' in the theory of Clair- 

 aut here presented is contained, beyond all 

 doubt, the idea that underlies the doctrine of 

 force-function or potential, which was afterwards 

 developed with such splendid results by Laplace, 

 Poisson, Green, Gauss and others.' (P. 398). 



In the section on mechanical units, adapted 

 to American usage by Mr. C. S. Peirce we no- 

 tice the suggestion that the unit of acceleration 

 be called a ' galileo,' as one more contribution 

 to supply ' a long felt want.' The suggestion is 

 at once adopted in the illustrations that follow. 



Under ' The formal development of mechan- 

 ics ' is presented a view of the characteristic 

 classes of problems that have arisen. This, 

 together with a discussion of the various points 

 of view, theological, animistic and mystical, of 

 the great investigators, a section on analytical 

 mechanics, and one on the economy of science, 

 makes a most readable and enjoyable chapter. 



The final chapter treats of the relations of 

 mechanics to other departments of science, and 

 is the least satisfactory one in the book. It opens 

 with the declaration that ' ' purely mechanical 

 phenomena do not exist;" an arbitrary assertion 

 which is explained by the equally arbitrary 

 one that ' with dynamic results are always as- 

 sociated thermal, magnetic, electrical and chem- 

 ical phenomena.' The statements are arbitrary 

 because there is no proof of them. The author 

 deprecates explaining all physical phenomena 

 by mechanical ideas, saying, ' ' we have no 

 means of knowing, as yet, which of the phys- 

 ical phenomena go deepest, whether the mechan- 

 ical phenomena are perhaps not the most super- 

 ficial of all, or whether all do not go equally 

 deep." Precisely; and for that reason, if for no 

 other, we would take exception to the opening- 

 remark quoted above. Even if it were shown 

 that no supposed mechanical phenomenon oc- 

 curred without one or more of the other effects 

 mentioned, the proposition would be by no 

 means proven. Attraction, repulsion and strain 

 are the Very essence of mechanics and it is by no 

 means certain that they are not the essence of 

 other branches of physics also. There is noth- 

 ing to show that magnetic, electrical and even 

 chemical phenomena may not be ultimately and 

 purely mechanical in their nature. 



The translation is occasionally very free, but 

 generally faithful to the meaning of the origi- 

 nal, and only varied from it in form, to make 

 the statements more lucid. This effect is 

 heightened by the insertion of several brief 

 notes by the translator. 



Reproductions of quaint old portraits and 

 vignettes give piquancy to the pages. The 

 numerous marginal titles form a complete epi- 

 tome of the work ; and there is that invaluable 

 adjunct, a good index. 



Altogether the publishers are to be congratu- 

 lated upon producing a technical work that is 

 thoroughly attractive in its make-up. 



D. W. Heeing. 

 Univebsity of the City of New York. 



On a Collection of Mammals from Arizona and, 



Mexico, made by W. W. Price, ivitli Field Notes 



by the Collector. By J. A. Allen. Bull. 



American Museum Natural History, vol. 



VII., pp. 193-258, June 29, 1895. 



This important paper is based chiefly on a 

 collection of 1500 specimens of small mammals 

 obtained by W. W. Price in 1894 in southeastern 

 Arizona. Mr. Price contributes an itinerary 

 and descriptions of localities at which collections 

 were made — a useful feature too often omitted 

 in faunal papers. He also attempts to define five 

 life zones, but fails to correlate them with the 

 zones now commonly recognized in the region. 

 His first is wholly Lower Sonoran ; his second com- 

 prises the upper part of the Lower, and lower 

 part of the Upper Sonoran ; his third is the up- 

 per or juniper belt of the Upper Sonoran ; his 

 fourth is the Transition, and his fifth the Boreal. 



The annotated list of mammals by Dr. Allen, 

 with Mr. Price's field notes, covers 58 pages 

 and is a great addition to the published I'ccord 

 of our knowledge of Arizona mammals. Several 

 changes in nomenclature are made and one 

 species is described as new (Thomomys cervinus, 

 a pocket gopher from Phoenix). The other 

 new forms were described by Dr. Allen in a 

 previous paper. Perognathus conditi and Per- 

 odipus chapmani are allowed to stand as species, 

 although it has not been shown how the former 

 differs from Perognathus paradoxus, or the latter 

 from Perodipus ordi. 



All of the wood rats are lumped under a 



