474 Mr. S. S. Richardson on Magnetic Rotary 



The values of n-p are those of Conrady, and R w is that of 

 Perkin. 



It will be seen that although the values of the linkages 

 are those deduced from R w lor a single substance in each 

 case, no attempt being made to work out mean values, a very 

 fair agreement between the observed and calculated values 

 is obtained. 



Turning now to the refraction, we have 



The values of P x 2 , &c. given by the magneti ^rotation for 

 the linkages (CC), (CH), CO), (OH) enable us to calculate 

 at once the corresponding values of P. 



(CH) = 1-353, (CO) = -574, 



(CC) = -415, (OH) = 1-173. 



The sum of the P's for the electrons of classes III. and IV* 

 of the atoms C, H, must first be calculated, for which we 

 may use the following values for the molecular refractive 

 power with reference to the D line. 



Pentane P = 25'17 



Hexane P = 29*71 



Ether P = 22-37 



Thus denoting the sums just referred to by the symbols- 

 C, H, and 0, we have 



29-71 = 5(CC) + 14(CH) + 6C + 14H 



= 21-015 + 60 + 14H, 

 25-17 = 4(CC) + 12 (CH) + 50 + 12H 



= 17-895 + 50 + 12H, 

 whence H = -087, C = 1*245. 



For the oxygen atom, 



22-37 = 2(CC) + 10(CH) + 2(CO) + 4C + 10H + O. 



Hence = 1-013. 



The two linkages of the carbonyl group cannot be 

 evaluated from the magnetic rotation, since the latter gives 

 the sum of the squares of the two P's, and these may not be 

 of equal value. We must obtain X(C0) therefore from the 



