34 



PHYSIOLOGICAL CHEMISTRY 



and uniformly light." The difference between this reading and the 

 zero is a or the observed rotation in degrees. 



Polarizing saccharimeters are also constructed by which the per- 

 centage of sugar in solution is determined by making an observation 

 and multiplying the value of each division on a horizontal sliding scale 

 by the value of the division expressed in terms of dextrose. This 

 factor may vary according to the instrument. 



FIG. 7. PCLARISCOPE (SCHMIDT AND HANSCH MODEL). 



"Optical" methods embracing the determination of the optical 

 activity are being utilized in recent years in many " quantitative " 

 connections. 1 



CH 2 OH 



I 

 FRUCTOSE (CHOH) 3 



CO 



I 



CH 2 OH 



1 Abderhalden and Schmidt: "Determination of blood content by means of the optical 

 method," Zeit. physiol. Chem., 66, 120, 1910; also C. Neuberg: "Determination of nucleic 

 acid cleavage by polarization," Biochemische Zeitschrift, 30, 505, 1911. 



