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II. The Specific Heat of Aqueous Solutions , with Special Reference to 
Sodium and Potassium Chlorides. 
Bij W. R. Bousfield, M.A., K.C., F.R.S., and C. Elspeth Bousfield. 
Received June 16,—Read June 28, 1917. 
Contents. 
Section Page 
1. -Introduction.119 
2. Apparatus and Method.121 
3. Calibration of the Mercury Thermometer-Resistance.123 
4. The Watt Balance.123 
5. Calorimeter Corrections.125 
6. Correction for Stirring and Evaporation.126 
7. Obturator Heating.126 
8. Radiation through Calorimeter Walls. 126 
9. Method of Calculation.127 
10. Specific Heat Observations.127 
11. Capacity of Calorimeter.129 
12. Specific Heat Measurements.130 
13. Density Observations. 131 
14. Final Specific Heat Values.133 
15. Relation between Specific Heat and Density. 137 
16. Volume Changes in Solvent.140 
17. Specific Contraction of Water of Solution.140 
18. Relation 6f Specific Heat Lowering to Specific Contraction.141 
19. Change in Mean Specific Heat of Water.143 
20. Relation of Heat of Dilution to Specific Heat and Contraction.116 
21. Specific Heat in Relation to Free and Combined Water.147 
22. Derivation of Specific Volume of Solute.149 
23. Analysis of Specific Heat of Solution.151 
24. Changes in Free Water of Solution.153 
1. Introduction .—When a solute is dissolved in water, some of the water usually 
enters into combination with the solute whilst the remaining free water undergoes 
certain changes in constitution. The total volume of the water is always diminished. 
This contraction of the water has in the past been correlated to various properties of 
solutions and light has in this way been thrown on the phenomena of solution. In 
this communication the matter is studied with reference to the specific heat of 
solutions by reference to the examples of potassium and sodium chlorides. Thomsen 
VOL. OOXVIII.-A 562. R [Published February 25, 1919. 
