X. Bakerian lecture .—On the Relations between the viscosity (internal friction) of liquids and their chemical nature

Abstract

During the half century which has elapsed since Hermann Kopp directed attention to the connection which exists between the molecular weights of substances and their densities, the attempts which have been made to establish similar relationships between the magnitudes of other physical constants and chemical composition have shown that probably all physical constants are to be regarded as functions of the chemical nature of molecules, and that the variations in their magnitude observed in passing from substance to substance are to be attributed to changes in chemical composition. The physical properties first investigated from this point of view were naturally those either often measured or at least capable of being easily measured. To this class belong such determinations as density, boiling-point, refractive index, &c., &c. On the other hand, properties not so clearly understood, or less readily perceived, received little or no attention. An example of this kind occurs in connection with the viscosity of liquids.