Prof. T. E. Thorpe and Mr. .!. W. Rodger. [Feb. 23 



JWrttary 22, 1894. 

 Thi- LORD KELVIN, D.C.L., LL.D., President, in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The Bakerian Lectnre was delivered as follows : 



BAKERIAN LECTURE. " On the Relations between the 



cosity (Internal Friction) of Liquids and their Chemic* 

 Nature." By T. E. THORPE, D.Sc., F.R.S., and .1. W. 

 RODGER, Assoc. R.C.S. Received February 22, 1894. 



(Abstract.) 



The purpose of this paper is to throw light upon the relations be- 

 tween the viscosity of homogeneous liquids and their chemical natui 

 It is divided into three parts. 



Part I contains a summary of the attempts which have been made, 

 more particularly by Poiseuille, Graham, Rellstab, Guerout, Pribram 

 and Handl, and Gartenmeister, to elucidate this question. Although 

 it is evident from the investigations of these physicists that relation- 

 ships of the kind under consideration do exist, it must be admitted 

 that they are as yet not very precisely defined, mainly for the reasoi 

 that the conditions by which truly comparable results can alone 

 obtained have received but scant consideration. 



For example, it seems futile to expect that any definite stoichu 

 metric relations would become evident by comparing observatioi 

 taken at one and the same temperature. Practically, nothing is known 

 of a quantitative character concerning the influence of temperature 

 on viscosity. 



From the time which a liquid takes to flow through a capill 

 tube under certain conditions, which are set out at length in 

 paper, a measure of the viscosity of the liquid can be obtained. 



An apparatus was, therefore, designed on this principle which ad- 

 mitted of the determination in absolute measure of the viscosity, anc 

 for a temperature range extending from up to the ordinary boilii 

 point of the liquid examined. In this way instead of finding, as has 1 

 the usual custom, relative times of flow in the same apparatus unde 

 the same external conditions of temperature and pressure, and wl 



