1869.] 



of Aqueous Mixtures and Solutions. 



335 



to the thread of alcoholic mixture contained in the second column, and 

 gives, therefore, a measure of the relative strength of the molecular attrac- 

 tion in the various mixtures. 



The experiments were made at a temperature of 16° C. 



Section 5. Bate of Expansion. 



This was determined by estimating the specific gravity of the different 

 mixtures at the temperatures 10° C, 15°'5 C, 20° C. 



The specific-gravity bottle has two necks ; into one was fitted a thermo- 

 meter with a long bulb, whilst the other ended in a capillary tube. 



This bottle was placed in a water-bath, whose temperature was under 

 perfect control, and thus the specific gravity could be accurately estimated 

 at the above-named temperatures. 



Section 6*. Compressibility . 



This property was estimated by an apparatus similar to the one employed 

 by Regnault and Grassi, but of simpler construction. 



The piezometer was of glass ; pressure was applied to the inside and out- 

 side by forcing air into the apparatus by means of a small pump ; 0*000002 

 was always added as a correction for the compressibility of the piezometer. 



The two following Tables give the results obtained in Sections 5 and 6. 



Percentage 

 of alcohol, by 

 •weight. 



Volume at 

 io°C. 



Volume at 20 C, 

 found. 



Volume at 20 C., 

 calculated. 



Difference. 



o 



100 



ioo-i 54 



100*154 



— •060 



IO 



100 



IOO - 2I2 



100-272 



20 



100 



100-405 



100386 



+•019 



3° 



ICO 



100-632 ' 



100-498 



+ ,;[ 34 



4° 



100 



100-783 



100*601 



+•182 



45 



100 



100-827 



100*652 



+'175 



5° 



100 



100-868 



100-700 



+•168 



59*77 



100 



100-914 



100-789 



+ •125 



6973 



iCO 



100-980 



100-874 



-f*io6 



79-81 



IOO 



IOI-020 



100-954 



+•066 



89-89 



IOO 



101*052 



101-034 



+•018 



ioo-oo 



IOO 



ioro88 



ioro88 





Percentage 

 of alcohol, by 



Compressibility 



Compressibility for 





for one 



one atmosphere, 



Difference. 



weight. 



atmosphere, found. 



calculated. 









0*00004774 



0*00004774 





10 



0*00004351 



0*00005387 



0-00001036 



20 



0-00003911 



0*00005998 



0*00002087 



30 



0-00003902 



0-00006584 



0*00002682 



40 



0*00004347 



0-00007118 



0*00002771 



45 



0-00004608 



0*00007366 



0-00002758 



50 



0-00004878 



0*00007600 



0-60002722 



5977 



0-00005620 



0*00008029 



0-00002409 

 0-00002267 



6 973 



0-00006159 



0*00008426 



78-81 



0*00006942 



0*00008775 



0-00001833 



89-89 



0*00007950 



0-00009140 



o-oocoi 190 



IOO'OO 



0-00009349 



0-00009349 





