February 13, 1914] 



SCIENCE 



251 



would have been able to write on paper. It 

 can be put on the slide as soon as the paraffin 

 ribbon has been mounted. If the slide was 

 clean when the label was written, water, 

 alcohol and xylol may be applied to it freely 

 without any danger of injury. Ordinary 

 abrasion such as the slide frequently encount- 

 ers in use will not in any wise affect the per- 

 manency of these labels. They can, however, 

 be scratched off easily with a dull knife (or 

 scrubbed off with scouring soap). A white 

 paper label pasted on the hach of the slide will 

 make it even more conspicuous. 



Lance Burlingame 

 Stanford Univebsitt, California, 

 January 14, 1914 



A JfEW NAME FOR THE MARMOT OF THE CANADIAN 

 ROCKIES 



Mr. Arthdr H. Howell has called my at- 

 tention to the fact that the name applied by 

 me to the large marmot from the Moose Pass 

 branch of the Smoky Eiver, Alberta, Marmota 

 sihila,^ is preoccupied by Arctomys sibila 

 Wolf .^ The marmot of the Moose Pass region 

 may be called Marmota oxyiona. 



N. Hollister 



U. S. National Museum, 

 November 5, 1913 



SCIENTIFIC BOOKS 



Mathematical Monographs. Edited by Mans- 

 field Merriman and Eobert S. Woodward. 

 No. 12. The Theory of Relativity. By 

 EoBERT D. Carmichael. New York, John 

 Wiley & Sons. 1913. Pp. Y4. 

 Unlike most presentations of the theory of 

 relativity, which contain a considerable amount 

 of technical mathematical physics, Carmi- 

 chael's is non-technical and logical in the same 

 way that the discussion of the foundation prin- 

 ciples of geometry or mechanics or chemistry 

 might be made non-technical and logical. 

 The book may, therefore, be read with ease by 

 the mathematician who has little or no knowl- 

 edge of modern physics or by the physicist 

 1 Smithsonian Miscellaneous Collections, Vol. 56, 

 No. 35, p. 1, February 7, 1912. 



2Liime's " Natursystem, " Vol. 2, p. 481, 1808. 



who is unacquainted with mathematical analy- 

 sis; it might be read by the engineer or, for 

 the most part, by the philosopher. The work 

 is in no sense a mere compilation from the in- 

 vestigations of previous authors, but repre- 

 sents a considerable amount of independent 

 investigation of which the major part has ap- 

 peared in contributions to the Physical Re- 

 view. 



The strongest and most satisfactory part of 

 the book is that dealing with the statement of 

 the postulates upon which the theory is built 

 and with the direct consequences of the postu- 

 lates. Less final and satisfactory are those 

 parts where the physical theories (as distin- 

 guished from the results of physical experi- 

 ments) which might conceivably underlie the 

 theory are mentioned. This lack of finality 

 and satisfaction is, however, quite unavoid- 

 able in these latter days when so many phe- 

 nomena apparently subversive of long-accepted 

 notions are constantly being unveiled. One 

 has only to read the report on " La Theorie du 

 Eayonnement et les Quanta," ^ of the col- 

 loquium held at Brussels in 1911 to see in what 

 a state of partial bewilderment and contradic- 

 tion are the leading physicists of our time. 

 The riot of new hypothesis and theory in the 

 last volume (No. 26) of the Philosophical 

 Magazine is a similar indication. 



The author abstains from electromagnetic 

 theory and confines his attention to the rela- 

 tion of the theory of relativity to the concepts 

 of length and time, of mass and energy; he 

 has, however, to mention that fundamental 

 unit of electricity, the electron. He does well 

 to emphasize the independence of the theory of 

 any hypothesis as to the existence or non-ex- 

 istence of the ether, even though he subse- 

 quently finds it useful to make use of the 

 ether in discussing the physical nature of 

 mass. He could profitably have gone a little 

 more into detail with regard to the relation 

 between the ether and relativity. 



Once we admit the existence of a stagnant 

 ether, we have at hand at least a logical fixed 

 system of reference; we may logically speak of 



1 Langevin and Broglie, Gauthier-Villars, 1912. 



