GANONG ANOXYSCOPE 



Demonstrates the Necessity of Oxygen to Plant Growth 



THE PLANT in the left-hand U-tube receives oxygen, the tube- 

 opening being immersed in water. The oxygen in the right-hand 

 U-tube is absorbed by pyrogalHc acid, preventing the growth of 

 the contained plant. 



Price, $4.25 



Our catalog of Ganong Botanical Apparatus completely describes 

 26 different pieces of apparatus. Shall we send you a copy? 



Bausch g' Ipmb Optical (g. 



NEW YORK 



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LONDON liOCH ESTER,, N.Y f^i^ANKroar 



Leading American Makers of Microscopes, Projection Lanterns (Balopticons), 



Photographic Lenses, Engineering Instruments, Stereo Prism Binoculars 



and other High Grade Optical Products 



