332 



GASOMETRIC-VOLUMETRIC METHODS 



potassium bicarbonate, and 0.5 g. saponin in distilled water and 

 make up to 50 ml. Do not use the soln. after 3 days. 



Acetate Buffer. Dissolve 70 g. sodium acetate (NaC2H302.3H20) 

 in 100 g. distilled water and add 15 ml. glacial acetic acid. 



i5% Urea (used as cleaning solution). 



10% Sodium Hydroxide. 



Pyrogallol Solution. Add 15 g. powdered pyrogallol to 100 ml. 20% 

 sodium hydroxide under a 2 cm. layer of oil. Dissolve the pyro- 

 gallol under the oil by stirring with a glass rod. 



PROCEDURE 



1. With the syringe analyzer in a vertical position and the 

 plunger pushed up, fill the cup with ferricyanide soln. Draw the soln. 

 down to the bottom of the syringe, push it back up into the cup, and 

 suck it out. Repeat twice with fresh lots of ferricyanide, taking care 

 to avoid trapping air bubbles. Leave the dead space in the syringe 

 full of ferricyanide. Use no grease or oil in the syringe. 



Fig. 106. Transfer of blood 



from pipette directly to capillary. 



From Roughton and Scholander (1943) 



Fig. 107. Further details 

 of the transfer of the blood 

 from the pipette to the 

 capillary. From Roughtoii 

 and Scholander (1943) 



2. Fill the glass cup to the mark with ferricyanide soln. and 

 draw it down to the bottom of the cup. 



3. Place a drop of caprylic alcohol on the bottom of the cup. 



