SCIENCE— ADVERTISEMENTS 



A Rubber Plant Survey 



of 



Western North America 



By Harvey Monroe Hall and 

 Thomas Harper Goodspeed 



I. Chrysothamnus NauseOsus and its Varieties. 

 Harvey Monrot; Halu 



n. Chrysil, a New Rubber from Chrysothamnus 

 Nauseosus. Harvey Monroe Hah and 

 Thomas Harper Goodspeed. 



m. The Occurrence of Rubber in Certain West 



American Shrubis. ^Iarvey Monroe Hall 

 And Thomas Harper Goodspeed. 



120 pages. 3 filalea. 8 figures in text. 

 $1.25 



The University <^ California Press 



Berkeley, California 280 Madison Ave, New York 



Is Your Chemistry 

 Curriculum Complete? 



Test and McLaughlin 's 

 Notes on Qualitative Analysis 



Is prepared for students who have had one 

 semester of general chemistry. It pre- 

 sents abroad knowledge of general chem- 

 istry, outlines briefly the underlying 

 principles of the Ionic Theory and Mass 

 Law and connects these theories with the 

 work of the laboratory. 



Ginn and Company 



Boston New York Chicago Lonbon 

 Atlanta Dallas Columbus San Francisco 



Visual Instj-uction 



WITH 



Spencer Delineascope 



MODEL 3 



is made perfect because it is an IDEAL 

 STEREOPTICON.for both lantern slides and 

 opaque objects, such as pictures, post cards, 

 reading- matter and objects of all kinds, dead 

 or alive. 



IDEAI^ because it 'embodies basic ideas 

 ( Patented ) possessed by no other. Example • 

 Mechanical means of handling the slides, 

 which does away with ^he old antequated lan- 

 tern-slide holder and at the same time gives 

 a "dissolving effect" on the screen, unat- 

 tained with other outfits except by using 

 two Stereopticons, one above the other. 



One Spencer Delineascope does it 

 New Booklet K*10 Jatt Ready 



Spencer DelineaBcope, Model 3, for both lantern ilides 



and opaque objects 



1000 Watt Mazda bulb llluminant. Price, $150.00 



SPENCER LENS COMPANY 

 BUFFALO, N. Y. 



MANUFACTURERS OF 

 MICROSCOPES, MICROTOMES, DELINEASCOPES, 



OPTICAL GLASS, SCIENTIFIC APPARATUS. ETC. 



