EXTRACTION OF THE BLOOD GASES. 



41 



places the bulb, E, in communication with the gas-delivery tube, h, and the eudiometer, J. 

 B, G, D are completely emptied of air, thus : The stop-cock is placed in the position, K ; raise 

 F until drops of mercury issue from the fine tube, % (not yet placed under J) ; place the stop- 

 cock in the position H, lower F ; stop- cock in position, K, and so on until the barometer, y, 

 indicates a complete vacuum. J is now placed over i. Open the cocks, c and b, so that the 

 blood-bulb, A, communicates with the rest of the apparatus, and the blood gases froth up in B, 







Scheme of Pfliiger's gas-pump. A, blood-bulb ; a, stop-cock, with a longitudinal perforation 

 opening upwards ; a', the same opening downwards ; b and c, stop-cocks ; B, froth-chamber ; 

 cl, e, /, stop-cocks ; G, drying-chambers, containing sulphuric acid and pumice-stone ; D, 

 tube, with manometer, y. 



and after being dried in G pass towards E. Lower F, and they pass into E ; stop-cock in 

 position, K, raise F, and the gases are collected in J under mercury. The repeated lowering 

 and raising of F with the corresponding position of the stop-cocks ultimately drives all the 

 gases into J. The removal of the gases is greatly facilitated by placing the blood-bulb, A, in a 

 vessel containing water at 60 C. 



It is well to. remove the gases from the blood immediately after it is collected from a blood- 

 vessel, because the undergoes a diminution if the blood be kept. Of course, in making several 



