332 C. E. Linebarger — Viscosity of Mixtures of Liquids, 



they had a less degree of fluidity than that calculable by the 

 rule of mixtures, and, in the case of the mixtures of ether 

 with chloroform and carbon bisulphide, points of inflection 

 were present in the curves representing the phenomena. 



Pagliani and Battelli"^ made some determinations at 0° and 

 10° of the internal friction of mixtures of methyl, propyl, 

 and ethyl alcohols with water. They discovered that these 

 mixtures all presented a maximum in viscosity, but that '^ La 

 ricchezza procentica alia quale corrisponde il massimo di attrito 

 diminuisce col crescere della temperatura, per cui si ha ragione 

 di credere che ad una data temperatura non si abbia pui questo 

 massimo, ma che il coefficiente di attrito delle mescolanze alcoo- 

 liche vada continuamente crescendo col crescere della propon- 

 zione di alcool in esse contennto." 



As a continuation of the work of these Italian physicists 

 may be considered the investigations of J. Traube,t who deter- 

 mined the viscosities of a number of aqueous solutions of sev- 

 eral of the organic acids and alcohols. 



S. Arrheniusij: also has measured the fluidity of some organic 

 liquids dissolved in water; his solutions were dilute, containing 

 10 percent or less of the dissolved liquid; he observed that 

 usually the viscosity of water is increased by the addition of 

 small proportions of non-electrolytic liquids, but, in a foot 

 note, states that a little acetone, ethyl ether, or methyl alco- 

 hol, when added to ethyl alcohol, lowers the degree of viscosity. 



An inspection of the determinations of the viscosity of 

 liquids recorded in the papers just mentioned brings to light 

 the fact that all mixtures, which have a maximum of internal 

 friction, contain at least one liquid which is known to be com- 

 posed of associated molecules ; also, that such mixtures as do 

 not present this maximum are made up of normal liquids. It 

 seems legitimate to infer, then, that there is an intimate rela- 

 tionship between the occurrence of a maximum of viscosity 

 in liquid mixtures and the molecular polymerization of the 

 liquids composing them ; indeed, it may be said that it is prob- 

 able that the maximum will be found only in such mixtures as 

 contain associated liquids. Another circumstance which 

 increases the probability of this statement is the fact that the 

 higher the temperature, the less pronounced the maximum, and 

 also, as is well kiiown, the less the degree of molecular com- 

 plexity. The curves given in Traube's paper are instructive in 

 this respect ; they are drawn with concentrations of the axis 



■^Sull'attrite interno nei liquid!, Annali del .R. Istituto Tecnico Germano Som- 

 meiller in Torino. XIII. Anno, 1884-1885. 



t Ueber die innere Reibungsconstante und die speeifische Zabigkeit organischen 

 Fliissigkeiten und ihrer wasserigen Losungen, Ber. deutschen chem, Gesell., xix^ 

 871-892, 1886. 



X Zeitschr. f. pbys. Chem., 1, 284, 1887. 



