i 



C. E. Linebarger — Viscosity of Mixtures of Liquids. 331 



Art. XLYIII. — On the Viscosity of Mixtures of Liquids i by 

 C. E. Linebarger. 



I. Historical. Object of Investigation. 



The earliest investigations of note on the viscosity or in- 

 ternal friction of solutions were carried out by Girard"^ and 

 Poiseuille f " The isolated discovery of M. Poiseuille, that 

 diluted alcohol has a point of maximum retardation, coincid- 

 ing vrith the degree of dilution at vi^hich the greatest con- 

 densation of the mixed liquids occurs," induced Grahamij: to 

 investigate mixtures of other liquids with water as regards 

 their rate of transpiration, as this appeared to him " to depend 

 upon chemical composition, and to afford an indication of it." 

 He made a number of determinations of the internal friction 

 of aqueous solutions of nitric, sulphuric, acetic, butyric, valeri- 

 anic, formic, and hydrochloric acids, as well as of ethyl alcohol 

 and acetone, finding that usually a maximum of the property 

 in question was observable. " It is remarkable," he writes, 

 "' that hydrated liquid compounds appear in general to show 

 only one decided transpiration maximum, as with the 1-hydrate 

 in sulphuric acid, the 2-hydrate in acetic acid, the 3-hydrate in 

 nitric acid, the 6-hydrate in alcohol, and the 12-hydrate in 

 hydrochloric acid." 



Wijkander§ determined the viscosity of mixtures of acetic 

 acid and water, aniline and benzene, ether and chloroform, 

 ether and carbon bisulphide, ether and alcohol, and benzene 

 and alcohol at temperatures between 0° and 60°. His results 

 for the mixtures of water and acetic acid corroborated those 

 by Graham for the same mixtures as regards the occurrence of 

 a maximum of the property in question ; the position of this 

 maximum, however, varied with the temperature at which the 

 determinations were carried out, a relation of any detiniteness 

 between chemical constitution and viscosity seeming not to 

 exist. Mixtures of such of the liquids employed by Wijkander 

 as were composed of normal molecules were found not to 

 exhibit a maximum of the property in question ; generally 



* Mouvement des fluides dans les tubes capillaires, Memoires de I'Institut, 1813, 

 1814, 1815 and 1816. 



f Recherches experimen tales sur le mouvement des liquides dans les tubes de 

 tres petits diametres, Annales de Chimie et de Physique, III, vii, p. 50, and xxi, 

 p. 76, 1848; also in Pogg. Ann., Iviii, 424, 1843. 



X On the Capillary Tranfipiration of Liquids in Relation to Chemical Composi- 

 tion, Chemical and Physical Hesearches, p. 601 ; and Philosophical Transactions, 

 1861, pp. 373-386. 



§ Ueber die Reibung der Plussigkeiten, Lunds. Physiog. Salsk Jubelskrift, 

 1878; Wied. Beiblatter, iii, 8, 1879. Only the reference in the " Beiblatter " has 

 been accessible to me. 



Am. Jour. Sci. — Fourth Series, Yol. II, No. 11. — November, 1896. 

 24 



