OF ARTS AND SCIENCES. 



415 



carbon and cliloi'ine gave those of the other elements in the same 

 table. Columns fourth, fifth, and sixth, in Table VII., have the same 

 signification as the corresponding columns of Tables V. and VI. 



TABLE VII. 



TABLE VIII. 



The results tabulated in V., VI., and VII., are suificient to show 

 that the interferential equivalents of compounds may, in many cases, be 

 computed with a tolerably close approximation from those of the con- 

 stituent atoms. The approximation is, however, much less close than 

 in the cases of mixtures. On the other hand, the rule fails entirely 

 with certain compounds. Thus, the six liquids of the aromatic series 

 forming group fifth of Table IV., present very marked exceptions. In 

 these cases, no values of the interferential equivalents of carbon, hydro- 

 gen, and oxygen, can be found which will enable us to compute the 

 molecular equivalents. Mr. Gladstone * has met with similar excep- 

 tions in the refractive equivalents of the benzol series, and suggests, 



* Journal of the Chemical Society [2] Vol. 8, p. 101. 



