BLOOD 



67 



coincided with those in the solvent water, and a second type 

 (in spring rats) in which the changes fall away from those of 

 the water. This indicates a participation in the second type 

 of other serum constituents than the water. The causes of this 

 difference are undetermined. 



TABLE 29 



Changes in refractive index as well as in the proportional amount of serum proteins 

 in albino rats at different ages 



To reduce the readings of the observed angle of refraction to 

 a common base -at 20°C., two formulas may be used. When 

 the reading is made from 20°C.-35°C. then 



I = i - 1.25 {t - 20°) (2) 



When the reading is made from 17.5° — 20°C. then 



7 = 1 + 1.25 (20° - t) (3) 



/ = corrected angle: i = observed angle: 

 1.25 = minutes rise for one degree; t = the observed temper- 

 ature. 



