260 



Chapter XVII 



Our conjecture that the change in the reaction was due to the 

 increase of lactic acid turned out to be entirely erroneous. Ryffel 

 obtained the following figures for the "lactic acid" in the blood of 

 various members of the party at Pisa, Col d'Olen and the Margherita 

 hut respectively. 



* The acidity is expressed in terms of lactic acid. 



From these figures it will appear that the lactic acid at Pisa and 

 Col d'Olen was practically the same, whilst at the Capanna Margherita 

 there was a sensible lactic acidosis. 



Our Monte Rosa expedition therefore left us in the following- 

 position. We found: 



(1) In common with previous workers that the higher the altitude 

 the less CO 2 in the alveolar air and presumably less in the blood. 



(2) The higher the altitude the more marked the acidosis in the 

 blood when the CO 2 is shaken out (4) . 



(3) At any altitude the acidosis and the diminution of C0 2 so 

 nearly balanced one another that the reaction of the blood remains 

 practically constant and the dissociation curve is therefore mesectic. 

 This is true at all events on a first approximation. It is only by 

 a statistical treatment of a great number of determinations' 5 ' that 

 a degree of meionexy, corresponding to a fall of about 7% in 

 K, may be discovered sufficient to give the respiratory centre the 

 slight stimulation (6) which would account for the increased ventilation 

 observed. 



Every man at rest has therefore a dissociation curve which remains 

 approximately constant in spite of changes in those individual factors 

 whose balance preserves the constancy of the curve, its form is a cal- 

 culable quantity involving almost fixed values of n and K. You might 

 label the man with these letters as a mark of his identity. What acid 

 is responsible for the acidosis in the blood is yet to be ascertained, it is 

 clearly not lactic acid or any of its close relations ; on the other hand 



