ADVANCED DEMONSTKATIONS 



CHAPTER XLV. 

 DETERMINATION OF THE GASES OF THE BLOOD, 



A Method of Determining the 2 and C0 2 in Small Quantities of 

 Blood (Barcroft and Haldane). The apparatus consists of a small 

 glass vessel attached by pressure tubing of small bore to a pressure 

 gauge also of small bore. The vessel is so arranged that the 2 of the 



FIG. 2C2A. Barcroft-Haldane blood -gas 

 apparatus. 



FIG. 262s. Blood-gas vessel. 



blood sample can be liberated within it by ferricyanide, and the 

 increase of pressure measured by means of a gauge. From the increase 

 of pressure the vol. of 2 can be calculated. By similar manipulations 

 with the use of tartaric acid the C0 2 is subsequently liberated and 

 measured. The apparatus is shown in Fig. 262A. One gauge A is con- 

 nected with the blood-gas vessel, and the other B with a precisely 



