338 Dr. A. Dupre on the Specific Heat fyc. [May 16, 



boiling-point of a mixture is influenced by its components in proportion to 

 their respective weights. 



Table III. 



Percentage 

 of absolute 



methylic 

 alcohol, by 



weight. 



Boiling-point 

 observed. 



Boiling-point 

 calculated. 



Difference. 







9993 



o 





10 



82-57 



95-80 



-13-23 



20 



75-26 



91-76 



16-56 



30 



70-68 



87-53 



16-85 



40 



68-31 



83-40 



15-09 



50 



67-08 



79-26 



11-18 



60 



65-75 



75-13 



9-38 



70 



64-65 



71-00 



6-35 



80 



63-13 



66-87 



374 



90 



60-96 



62-73 



1-77 



100 



5S-60 







Section 4. Capillary Attraction. 



This is estimated by means of an apparatus similar to the one employed 

 by Gay-Lussac, the height being measured by a cathetometer. Two 

 capillary tubes are employed, and the mean taken. The third column in 

 Table IV. gives the length of a column of water equal in weight to the thread 

 of alcoholic mixture in the second column, and affords, therefore, a measure 

 of the relative strength of the molecular attraction in the various mixtures. 

 The heights in column 4 are calculated on the assumption that they will be 

 proportional to the weight of the constituents. 



The experiments are made at a temperature of 13°*5 C. 



Table IY. 



Percentage 

 of methylic 

 alcohol, by 

 weight. 



Height, as- 

 suming water 

 = 100milhms. 



Relative mole- 

 cular attrac- 

 tion. 



Height cal- 

 culated. 



Difference. 







100-000 



100-000 







10 



68-820 



67-818 



93-334 



-25 416 



20 



58-830 



57264 



86-667 



29-403 



30 



52-463 



50-381 



80-001 



29-620 



40 



48-947 



46-252 



73- 335 



27-083 



50 



46-538 



43136 



66-668 



23-532 



60 



46-467 



42-170 



60002 



17-832 



70 



45-176 



40 034 



53-336 



13-302 



80 



43-997 



37-955 



46-669 



8-714 



90 



42-612 



35-671 



40003 



4-332 



100 



40-970 



33-337 







