SCIENCE— ADVERTISEMENTS 



TOLMAN 



Theory of the Relativity 

 of Motion 



With Appendix 



A supplement to this work, written by the 

 author, has just been issued. Under the 

 title. 



Relativity Theories in Physics 



this Appendix gives a general description 

 of the nature of relativity theories, to- 

 gether with brief discussions of Tolman's 

 theory of similitude or relativity of size, 

 of Einstein's theory of the relativity of 

 uniform motion, and of Einstein's theory 

 of gravity and general relativity. 



ix + 242 pages (including Appendix). 

 Cloth, $1.75. Carriage extra. Weight, 

 IJ^ pounds. 



Appendix only (paper), 25 cents. 



The University of California Press 



BERKELEY. CALIFORNIA 



New Blakiston Books on 

 Chemistry 



HOOD AND CARPENTER. Textbook of 

 Practical Chemistry. 162 Illus. Cloth, 



J5.00. 



McGUIGAX. Introdnctlon to Cliemlcal 

 Pharmacology. Cloth, $4.00. 



ATJTENREITH. Detection of Poisons and 

 Strong Drugs. A Laboratory Manual. 

 Illus. Cloth, $3.50. 



MOL.INARI. Treatise on General and In- 

 dnstrial Organic Cliemlstry, 254 Illus. 



Cloth, $S.OO. 



SCHNEIDER. Microanalysis of Powdered 

 Vegetable Drugs. 237 illus. Cloth, 

 $5.00. 



SMITH. Priestley in America. Cloth, 



$1.50. 



COPAUX-IiEFFMANN. Introduction to 

 General Chemistry. 30 illus. Cloth, 

 $2.00. 



DREAPER. Notes on Chemical Research. 



Cloth, $2.50. 



JOBLING. Catalysis and Its Industrial 

 Application. 2d Bdi. Cloth, $2.25. 



P. Blakiston's Son & Co. 



Publishers Pfailadelphi* 



SPENCER SUPREMACY 



IN MICROTOME BUILDING 



IS SHOWN IN 



ROTARY MICROTOME 



No. 820 



The only Rotary Microtome ever built 

 with an 



INCLINE-PLANE- FEED 



It completely overcomes all the inaccuracies 

 usuallj' encountered in other rotary microtomes, 

 due to the up-and-down movement of the object. 



In this microtome the feed and the up-and-down 

 movement are ENTIRELY INDEPENDENT. 



SPENCER ROTARY MICROTOME No. 8N 



ITS SUPREMACY 



has gained for it an international reputation for perfection. It is in use in every 

 important laboratory in United States and in leading laboratories throughout the 

 world. Prompt deliveries now. 



SPENCER LENS COMPANY, Buffalo, N. Y. 



MANUFACTURERS 



Microscopes, Microtomes, Delineascopes 



