SECTION IV. 

 RESPIRATION. 



CHAPTER XII. 

 ANALYSIS OF AIR. ALVEOLAR AIR. APNOEA. 



Experiment 49. 



The (Haldane) gas burette A (Fig. 32) has a capacity of 10 c.c. of which 

 7 c.c. are contained in the bulbar portion and 3 c.c. are on the tubular portion. 



The latter is graduated to ths of a cubic centimetre. These proportions 

 100 



are chosen so that the oxygen in atmospheric air may be measured. The 

 burette is connected with a reservoir containing mercury B by rubber tubing 

 of sufficient length so that when B is placed on the upper hook (1) the mercury 

 will fill the burette. On this tubing, near the burette, are a screw clip (a) 

 and -a pinch cock (b). When the reservoir is hung on hook (2) the mercury 

 should stand at the 10 c.c. mark in the burette. At the upper end of A is 

 a three-way stopcock (c) opening, according to its position, either with the 

 outside or into a side tube which is connected by thick walled rubber tubing 

 (g) with thfe absorption bulb D. On the tubing above the bulb is a much 

 smaller bulb, E, and the lower end of the absorption bulb is attached to a 

 reservoir, F. A sufficient amount of 20 per cent, solution of NaOH is placed 

 in D and F to a mark on the tube between D and E. The gas burette is 

 surrounded by a water jacket and the whole apparatus is mounted on a 

 wooden stand. 



As described the apparatus is suitable for determination of 

 the CO 2 in alveolar air. If it is desired also to determine O 2 

 (either in atmospheric or alveolar air) the absorption apparatus 

 shown in the inset of Fig. 32 must be attached at the joint G. 

 This will be described later. 



Analysis for CO 2 alone. The first step is to test the 

 apparatus for leaks. Turn C in the position shown in I so that 

 the burette communicates directly with the outside. With 

 both screw clip (a) and pinch cock (b) closed, the reservoir is 

 then placed on hook I, after which first a and then b are partly 

 opened so that the mercury slowly rises in the burette and 

 displaces the faintly acid solution with which it was left filled. 



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