CHAPTER XVI 



THE EFFECT OF EXERCISE ON THE DISSOCIATION CURVE 



OF BLOOD 



So far the effect of exercise upon the dissociation curve of blood 

 has been but slightly studied. No doubt there is a great field for 

 work in this direction. What information there is, however, bears 

 directly upon the relation of the reaction of the blood to the activity 

 of the respiratory centre. 



Investigations have been made upon the dissociation curve of 

 blood before and after a climb of 1000 feet from the sea level, or 

 nearly so. For this purpose Carlingford Mountain, in the North of 

 Ireland, was chosen. On that mountain a climb of 1000 feet was 

 marked out. The first experiments were made by myself. I chose 

 a rate of climbing which did not entail any sort of " distress." 

 Roughly speaking this meant going up at the fastest rate at which 

 respiration could comfortably be performed through the nose. As 

 the results of these tests it seemed that 30 minutes for the climb was 

 a suitable speed ; 25 minutes was to me a definite effort whilst 

 anything slower than 30 minutes gave the impression of loitering. 

 I am of course fully conscious that any such subjective index is of 

 the roughest possible character, that probably one changes from day 

 to day and that what appears to be an effort one day is not so on 

 another. It is difficult, however, to arrive at any standard for moun- 

 tain climbing ; the staircases of some of the tube stations in London 

 would form a very good standard course for ascents of varying 

 degrees of rapidity. We however desired something which could be 

 compared more definitely with an Alpine climb, to which I shall 

 refer presently. The equipment which I took on the actual ascent 

 consisted in a couple of Haldane's vacuous tubes for the collection of 

 alveolar air, a long rubber tube for the same, some clean needles with 

 which to prick my finger, a crucible in which to whip the blood and 



