190 Dr. Wright and Messrs. Thompson and Leon. \\"\'b. 1: 



In neither of these experiments is there any difference in com- 

 position observable to an extent greater than might readily be sup- 

 posed to be due to experimental errors, including those caused by 

 differences in laboratory temperature at different times whilst making 

 the observations. 



In the following two experiments only the acetic acid was deter- 

 mined : 



Experiments with Approximately Conjugate Alloys of Lead, Tin, and 



Zinc. 



The experiments above described most strongly suggest that when 

 interfering causes are removed, so that the mixtures of liquids dealt 

 with can sensibly attain a condition of equilibrium, truly conjt 

 pairs of mixtures are formed, as 'supposed by Sir G. G. Stokes, 

 such a nature that the two may be intermixed in any proportioi 

 without any alteration in composition being thereby caused, 

 sumably the chief interfering cause in the former experiments 

 lead, zinc, and tin lay in the difficulty of obtaining thorough in! 

 mixture by simply stirring vigorously in a hot crucible; it might, 

 therefore, be expected that if, instead of stirring together the three 

 metals melted en masse, they were divided into two fractions and 

 separately melted in >iJch proportions as to produce two masses of 

 approximately the composition of a pair of conjugate alloys, and these 

 alloys were then mixed together and well stirred, a nearer approxima- 

 tion to truly conjugate compositions might be attained. We tried 

 several experiments in this direction, but the results were far less 

 sharp and well defined than those obtained with chloroform, wate,r, 

 and acetic acid, where a much more thorough intermixture by agita- 

 tion in a closed vessel could be readily effected. 



Thus, in one set of experiments we first prepared two alloys of 

 approximately conjugate composition for a temperature of about 800 

 (Part II, ' Boy. Soc. Proc.,' vol. 48, p. 29), viz. : 



