Jan. 13,19*3 
New Respirometer for Seeds 
105 
one experimental period. By making the pressure readings the basis 
of direct calculations both of oxygen consumed and of C 0 2 given off the 
multiplication of operations and errors involved in a combination of 
manometric and analytic methods as used by Bonnier and Mangin ( 2) 
and by Aubert (/) is avoided. A number of different forms of apparatus 
embodying these principles have been constructed and tried, the one 
here described being finally adopted as giving most satisfactory results. 
DESCRIPTION OF THE APPARATUS 
The apparatus (fig. 1) consists of (1) a cylindrical glass tube (A), in 
the form of a bottle, which is closed by a ground glass stopper (B), 
upon which are mounted a short open manometer of 2-mm. bore (C), 3 
and an inlet or leveling tube (D) provided with a small chamber (E) for 
the reception of the caustic which is to be used for the absorption of 
the C 0 2 ; and (2) a one-piece porcelain container (F) for the seeds. 
* The bore of the manometers should be at least a mm. and may be 2.5, or 3 mm. If the bore is less 
than 2 mm., the mercury does nor move freely enough to insure accurate work. 
