DEMONSTRATION 

 RESPIROSCOPE 



An instrument designed by Professor Ganong for proving that plants 

 release carbon dioxide in growth. Complete, as illustrated, $ 4' • ^ 3 • 



One of the new pieces described in the forthcoming new Ganong Appa- 

 ratus catalog which will be sent free on request. 



Bausch ^ Ipmb Optical (p. 



NEW YORK WASHINGTON CHICAGO SAN FRANCISCO 



LONDON I^OCHESTEa,N.Y. f^I^ANKrORX 



