312 



PHYSIOLOGICAL CHEMISTRY 



Position 1 



dioxide content of the plasma is illustrated in Fig. 100. It is made 

 of strong glass in order to stand the weight of mercury without danger 

 of breaking, and is held in a strong screw clamp the jaws of which are 



lined with thick pads of rubber. 

 In order to prevent accidental 

 slipping of the apparatus from 

 the clamp, an iron rod of 6 or 

 8 mm. diameter should be so 

 arranged as to project under 

 cock/ between c and d. 



Three hooks or rings at the 

 levels i, 2, and 3 serve to hold 

 the levelling bulb at different 

 stages of the analysis. The 

 bulb is connected with the bot- 

 tom of the apparatus by a 

 heavy walled rubber tube. 



It is necessary, of course, 

 that both stop cocks should be 

 properly greased and air tight, 

 and it is also essential that they 

 (especially /) shall be held in 



i mm. bore 



Position 2 V-/50CC 



3 mm bore 



Supporting 

 Rod 



Paraffin Oil- 



Position 3 

 is eo cm below 

 position z 



FIG. ioo.- VAN SLYKE CARBON DIOXIDE AP- FIG. II-- TUB E USED IN COL- 

 PARATUS. (Journal Biological Chemistry, 3, **9, ACTING BLOOD (Journal Biological 

 30 347, TOT*.} Chemistry, 30, 289, 1917.) 



