The metabolism of the Hood itself 121 



quantity of oxygen ; these incomplete products of metabolism have 

 been studied by Pfliiger and more recently by Krogh and others* ; 

 once oxidised they are done with ; they have nothing to do with 

 the subject which we are about to discuss. In the second place we 

 have a call for oxygen which may be attributed to the life of the 

 corpuscles of the blood itself. This is a steady oxidation which goes 

 on from hour to hour. 



As regards the life of the red corpuscles a natural line of inquiry 

 was that adopted by Warburg, namely to get some idea of the im- 

 portance of the nucleus to the metabolism of the corpuscle. He 

 therefore compared the metabolism of healthy human blood with that 

 of avian blood. 



The method was very simple. The blood was obtained aseptic- 

 ally (as shown by cultures in bouillon), centrifugalised in sterile salt 

 solution and received in two glass bottles of 3c.c. each. In these 

 bottles were some glass beads. The corpuscles and the salt solution 

 were thoroughly mixed by shaking, the oxygen in the blood of the 

 one was estimated at once, the other was incubated for a given time. 



The following results were obtained for human blood : the degree 

 of reduction is obtained by dividing the difference between the 

 oxygen in the two samples by the oxygen in the original blood, and 

 then multiplying by one hundred. 



No. 1 No. 2 



Duration of incubation ... 3 15 17 20 hours 



Degree of reduction 3 % 5% 9% 10% 



In rabbit's blood the rate of reduction is considerably greater. 



Duration of incubation ... 2| 2| 8 7 8 12^ hours 



Degree of reduction 8% 8 / 22% 19% 31% 29% 



As compared with these it will be seen that the metabolism of the 

 nucleated corpuscles of the goose is very great, and is maintained at 

 a fairly even level. 



Duration of incubation ... 150 102 150 minutes 



Fluid in which corpuscles) Kinger without 



are suspended . . . j P lasma NaHC0 3 Friedentl 



Reduction per hour 33% 32% 33% 



* Whilst this book has been in the press a very instructive paper on this subject 

 has appeared by Evans and Starling, Jo urn. of Physiol., XLVI. 



