38 



Chapter III 



warmed up rapidly by replacing the water in the bath by water at 

 a higher temperature. The flow of nitrogen then was resumed at 

 the altered temperature. 



Nitrogen was allowed to run for 35 minutes, by which time the 

 haemoglobin was slightly reduced. An analysis showed that 6 / of 

 the haemoglobin was reduced haemoglobin and 94 % oxyhaemo- 

 globin. The point at which we have arrived is represented as D in 

 Fig. 19. There is possibly an error of about 2 / in this measurement 

 either way, i.e. the percentage saturation may have been 92% or 

 96 / (d or d'\ The nitrogen was now stopped, the temperature of the 

 bath was raised to 38 C. (the time which the process took is omitted 



100 

 90 

 80 

 70 

 60 

 50 



B C 



40 

 30 

 20 



ia"c 



\ 



10 20 30 40 50 60 70 80 90 100 



FIG. 19. Curve representing the calculated degree of dissociation at any time of haemo- 

 globin which was reduced by a stream of nitrogen bubbled at a uniform rate. 

 Percentage saturation plotted vertically, time in minutes horizontally. The points 

 represent actual determinations, A D at 18 C., D G at 38 C. 



from the diagram) and the nitrogen was restarted. The haemoglobin 

 now reduced very rapidly. After this three other determinations 

 were made as follows : 



Point on curve D 



Time (minutes) measured from D 



Percentage saturation of haemoglobin ... 94 % 



E 

 7-5 



77% 



F 

 23 



60% 



G 

 53 



26% 



Thus whilst at 18 C. 35 minutes had been required for the reduction 

 of the haemoglobin from 100 % to 94 % saturation, at 38 C. it only 

 required 7'5 minutes to reduce it from 94 / to 77 / . Perhaps 

 the best comparison of the times necessary to produce a given 

 reduction can be obtained by extrapolating the curve DEFG back- 

 wards to B, in which case AC represents the time necessary to 



