BETWEEN THE VISCOSITY OF LIQUIDS AND THEIR CHEMICAL NATURE. 599 
Isomeric Ketones. 
Difference. 
DietLyl ketone. 
Jklethyl propyl ketone. 
222 
234 
12 
Ethylene chloride gives a coefficient which is markedly larger than that of ethylidene 
chloride. Here the symmetrical isomer has the larger value. In the case of the 
isomeric ketones, however, the symmetrical compound has slightly the smaller coeffi¬ 
cient. The probable cause of this result has already been indicated. 
Aromatic Hydrocarbons. 
Difference. 
Ortho-xylene. 
247 
-28 
ileta-xylene. 
219 
1 
Para-xylene.. 
220 
13 
Ethyl benzene. 
233 
Meta- and para-xylene have identical coefficients, which are, however, removed from 
that of ortho-xylene, which is some 30 units larger. The value for ethyl benzene is 
between that of ortho-xylene and of the other two isomers. 
General Conclusions relating to Viscosity Coefficients at the Boiling-'point. 
The results arrived at from the previous discussion may be summarized as follows:— 
(1.) As an homologous series is ascended, in a few cases the viscosity coefficients 
remain practically the same, but in the greater number of series the coefficients 
diminish. 
In one series the coeflScients increase. 
In the case of the alcohols the coefficients vary irregularly with ascent of the series. 
(2.) Of corresponding compounds, the one having the highest theoretical molecular 
weight has in general the highest coefficient. 
The acids and, to a much greater extent, the alcohols do not accord with this rule. 
(3.) Normal propyl compounds have, as a rule, slightly higher values than allyl 
compounds ; in the case of the alcohols propyl compounds have much the higher value. 
