VAPOR FRICTION OF ETHERS 311 



ous observers. The calculations were made according to Poi- 

 seulle's formula, very few corrections being necessary. 



From the study of isomeric ethers, as well as ethyl alcohol, 

 it was found that the constitution has a decided influence 

 upon the internal friction of the vapor, as will be seen from 

 the following table, representing in each case the average 

 of a number of experiments. The last column gives the com- 

 parative volumes of the molecules according to the formula 

 suggested by L. Meyer, in which Y is the friction, M the 

 molecular mass. 1 



Substance Y V 



Methyl ether, (CH 3 ) 2 O 1133-5 55-53 



Ethyl alcohol, C 2 H 6 O 1100 58-09 



Methyl-ethyl ether 1030 78-2 



Ethyl-ether 944-7 110-4 



Methyl-propyl ether 951-8 100-74 



Methyl-isopropyl ether 992-3 96-46 



Ethyl-propyl ether 874-9 133-2 



Di-propyl ether 797-6 170-7 



Di-isopropyl ether 841-5 157-8 



1 The editor has been unable to find the original source of this equation, which 

 is doubtless of a highly hypothetical nature. 



