96 
DR. T. E. THORPE AND MR. J. W. RODGER ON THE RELATIONS 
Conclusions relating to the Graphical Representation of the Results. 
Both ethers and esters give no evidence of molecular aggregation and conform to 
the rules that— 
(1.) In homologous series the viscosity is greater the greater the molecular weight. 
(2.) An iso-compound has a smaller viscosity then a normal isomer. 
(3.) The more symmetrical the molecule of an isomeric compound the lower is the 
viscosity. 
As regards the esters themselves it is noteworthy, where the comparison has been 
made, that— 
(4.) Of isomeric esters the formate has the largest viscosity. 
Algebraical Bepresentation of the Results. 
The following table gives the values of the constants in Slotte’s formula for the 
esters and ethers. Here the formula is written in the shape g = C/(l + 6^)" instead 
of that already used, viz., g = C/(a -f- ^)". C is, of course, the value of g at 0°, and 
since, in general, the curves do not cross one another, relationships exist between the 
values of C for the different substances similar to those just discussed and which 
hold regarding the position of the viscosity curves. 
Constants in Slotte’s formula g = C/(l -f hty . 
C. 
b. 
71. 
Methyl formate. 
•004301 
■014655 
0-8325 
Ethyl formate .... 
•005048 
•007197 
1-7006 
Propyl formate .... 
•006679 
•007179 
1-9154 
Methyl acetate .... 
•004781 
•006472 
1-8636 
Ethyl acetate .... 
•005783 
•007384 
1-8268 
Propyl acetate .... 
•007706 
■007983 
1-8972 
Methyl propionate. 
•005816 
■006820 
1-8972 1 
Ethyl propionate . 
•006928 
•007468 
1-8914 ! 
Methyl butyrate . 
•007587 
•0U8081 
1-8375 
Methyl isobutyrate 
•006720 
•007144 
1-9405 
Diethyl ether .... 
•002864 
•007332 
1 -4644 
Methyl ])i-opyl ethei' . 
•003077 
•006809 
1-5863 
Ethyl propyl ether 
•003969 
•005454 
2-1454 
Dipropyl ether .... 
•005401 
•006740 
1-9734 
Methyl isohutyl ether 
•003813 
•005737 
2-0109 
Ethyl isobutyl ether . 
•004826 
•006549 
1-9733 
Since the values of a and h are interdependent, their individual magnitudes need 
not show any definite relationships to the chemical nature of the substances. It is 
easy to prove, however, by the method already adopted, that the temperature 
