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Chapter VIII 



of the tumours. The interpretation of this would have been the 

 bigger the tumour the more acid the blood. My suspicion was 

 aroused by the great degree of reduction which some of the blood 

 underwent. This caused me to do control experiments in which I 

 treated some of the same blood with air instead of 17 mm. of oxygen ; 

 these control experiments led us to suspect that the blood reduced 

 itself. 



A second series of experiments were undertaken for the object 

 of testing this point. The technique was simple. The rats were 

 killed by cutting the throat. The blood was whipped with feathers, 

 thoroughly saturated with air and placed in a 1 c.c. glass syringe. 

 Care was taken to prevent air entering the syringe which was placed 

 in an incubator at 37 C. for f hour. The blood was then expelled 

 into the bottle of a differential apparatus under ammonia. The 

 percentage saturation was measured in the usual way, and as a known 

 quantity of blood was used the total oxygen capacity was also 

 obtained. 



Many of the samples showed a great degree of reduction. In 

 the series there were two classes of animals, those with tumours of 

 5 grams and under and those with tumours of 13 grams and over. 

 The blood which reduced itself to a great degree during the 

 45 minutes incubation came in each case from the rats with large 

 tumours, but the degree of reduction followed the total oxygen 

 capacity of the blood more closely than the weight of the tumour. 

 Roughly speaking the more anaemic the rat the greater was the 

 amount of reduction in the blood. The following table gives the data. 



Fig. 70 represents these data in the order of the haemoglobin 

 value showing how close is the correspondence between the degree 

 of anaemia and the power of the blood to eat up its own oxygen. 



