Rate of reduction of haemoglobin 



37 



Hill. Nitrogen was bubbled through a suitably protected solution of 

 haemoglobin at a constant rate but at two different temperatures. 

 The rate at which the haemoglobin was oxidised was noted in each 

 case. The experiment was first performed as follows. We started 

 at a temperature of 18 C. with the blood fully saturated. The 

 course of the experiment may be followed by reference to Figs. 18 

 and 19 ; the former shows the apparatus used, the latter the results 

 obtained. As regards the apparatus, the haemoglobin solution was 

 placed in the cylinder A. Nitrogen was passed at a constant rate in 



/Vitroofn, from, 

 Marnotte'sBottU M 



f/t-trootn, to 



i Bottle N 



. JL--. 



FIG. 18. Apparatus for the determination of the rate of oxidation of haemoglobin. 



the direction of the arrows, first through a wash-bottle containing 

 an alkaline solution of pyrogallol, then through the haemoglobin 

 solution ; the whole apparatus was immersed in a water-bath and in 

 that was kept at the required temperature. Samples of haemo- 

 globin, which were small relative to the whole volume of haemoglobin 

 used, could be abstracted from A at any time through a tube let in 

 through the cork for the determination of the percentage saturation 

 with oxygen. At any time in the experiment the inlet and outlet 

 tubes for the nitrogen could be clamped and the whole apparatus 



