Optical Activity of Solutions. 



819 



The object of the present communication is to show how a 

 simple modification of Drude's theory, based on almost 

 unassailable theoretical considerations, provides a very good. 



Fig. 1. 





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1 



— 4 











— J 







^**+*~ 







^^X*3 



* r 

 <0 





















" ' h- 















/i 





o 





Con 





C. . 



S 



-a '« 



■■ * 















-is 













explanation of all of the above-mentioned experimental 

 results. A general formula is obtained which includes- 

 formulse (i.) (ii.) and (iii.) as approximations, and also 

 provides us with the equation of the more general form of 

 curve given in the graph. 



2. General Tlieory. 



In the modern electromagnetic theory of optics we have 

 always to deal with the electric and magnetic force and the 

 electric and magnetic flux, such that each flux is derived 

 from the other force by the universally valid circuital 

 relations. If we denote the electric and magnetic force- 



