76 GENERAL AND PHYSICO-CHEMICAL. 



for the electrometric determination of reaction in fluids containing 

 carbon dioxide. By the aid of this method HASSELBACH and LUNDS- 

 GAARD l have made determinations of the reaction of the blood. From 

 these it follows that at a temperature of 38.5 C. where the value for 

 p H = 6.78 corresponds to the neutral reaction the figure obtained for PH 

 with defibrinated ox-blood was 7.36 showing therefore a slight alkaline 

 reaction. The influence of the respiratory variation in the CO2 tension 

 upon the H ion concentration of the blood is of a measurable size. 

 The total blood, has a greater H ion concentration than the serum at 

 equal CCb tension but less than the blood corpuscles. For human blood 

 saturated with C02 under 40 mm. tension at 38 C. LUNDSGAAKD 2 

 found p H = 7.19. MICHAELIS and DAVIDOFF S found the average values 

 of normal venous blood for pn = 7.35 at 37.5 C. 



1 Biochem. Zeitschr., 38, 77 (1911). 

 2/fod., 41, 2641(1912). 

 *Ibid., 46, 131 (1912). 



