EFFECT OF TEMPERATURE ON HEMOGLOBIN 181 



effect on the rate at which oxyhaemoglobin can be reduced is that 

 used by Hill and myseK(5). Nitrogen was bubbled through a suitably 

 protected solution of oxyheemoglobin at a constant rate but at two 

 different temperatures. The rate at which the oxyhsemoglobin was 

 reduced was noted in each case. The experiment was performed thus: 

 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. 60 and 61 — the former shows the apparatus, the latter the results 

 obtained. As regards the apparatus the haemoglobin solution was 



Afitrogen, /ronv 

 Ara,rr,otte-> BottU, M 



A/Ctroqtn, Co 

 Atarr/otiei Bottle N 



Fia. 60. Apparatus for the determination of the rate of reduction 

 of a haemoglobin solution. 



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

 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 in which 

 it was kept at the required temperature. Samples of haemoglobin, 

 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 oxygen saturation. At any 

 time in the experiment the inlet and outlet tubes for the nitrogen 



