The Effects of Salts on Haemoglobin 



total activity a° was estimated by assuming that these salts have 

 similar activity coefficients to ammonium sulphate and ammonium 

 chloride respectively. 



The figures marked b t (obs) may be subject to correction. A value 

 of b t = 2-3 instead of 2-7 for pH 7-08 was obtained in an experiment 

 made at a later date, using different analytical methods. Analytical 

 data used for estimating the excess coefficients in Table HI were 

 summarized by G. S. Adair and M. E. Adair 6 



Table HI 



Total excess coefficients for CO Haemoglobin (sheep) at 0°C. / = ionic 



strength of buffer mixture with 50 per cent (NH 4 ) 2 P0 4 + 50 per cent 



NH 4 H 2 P0 4 . m° POi = molality of total phosphate in the dialysate. 



m° = sum m° POi + m° NH ^ 



The last column headed b t (calc) gives values for b, computed by an 

 empirical formula with two constants. The first constant, k 1 =22-2±5. 

 The second constant k 2 was estimated as 3-4. 



b t {calc) = kj (<£)» -k 2 < ....(5) 



On the assumption that formula 5 is valid over the range from 



a° = 0-00 to 0-17 an estimate of the effects of sodium, ammonium or 



phosphate ions over the same range can be made by formulae 6 and 7 



d log T p (salt effect) = - b t d log a° t ... .(6) 



log y„ (salt effect) = - 0-4343 [2 k x «)* - k 2 af] ... .(7) 



The first effect of salts is to diminish y p in accordance with formula 7. 

 In a molar solution, where b t is negative, salts tend to increase the 



187 



