BLOOD 



65 



Moreover when the percentage of solids in the serum is 

 plotted on the refractive index, the relation between them is 

 seen clearly. The refractive index, when normal, is similar in 

 the two sexes but may be modified by fasting, defective diet, 

 gonadectomy and disease. 



Using data for the relation between the refractive index of 

 the serum and age as determined by Hatai ('21), Hammett 

 ('23 b) has obtained a formula (loc. cit.) which applies between 

 the ages of 34 and 160 days and by the use of this formula the 



TABLE 28 



The tabulated values of the refractive index of the blood serum of the albino rat on 



age in days 



reference values for the refractive index on age as given in 

 table 28 were obtained. 



The index of refraction is a linear function of the concentra- 

 tion of the solute. 



The percentage of water on the refractive index of the serum 

 where x is the refractive index and y the percentage of water 

 is given by the formula. 



1 - 0.0012445 y (1) 



x = 



0.65607 



