Capillarity of Molten Bodies. 95 



I) 



V. 



VI. 



VII. 



Yin. 



millims. 



millims. 



millims. 



millims. 



= 50-3 



50-3 



50-3 



(17°?) 



19°-44 



19°- 



8 



millims. 



millims. 



millims. 



millims. 



4-345 



4-033 



4-016 



4047 



4-23.2 



4-0.24 



4-036 



4-018 



4-284 



4-040 



4-000 



4-047 



Mean . 4*287 4-03:2 4-013 4-047 



Between the series VII. and VIII. of these experiments the 

 water, which had been previously purged of air, was shaken about 

 and mixed with it, so that, within the limits of observation-error, 

 water void of air and ordinary water seem to have the same con- 

 stant of capillarity. 



In the case of water which had stood in the bottles for several 

 weeks shut off from the air, we had : — 



IX. X. XI. 



millims. millims. millims. 



D=52"7 50-3 50-3 



Temp. 13°-1 17°'48 18°-05 



millims. millims. millims. 



3-922 3-910 4-075 



3-900 3-868 4-025 



3-899 3-824 4-Q07 



Mean . 3-907 3-867 4-036 



If the water is left some time in the same glass vessel, the 

 elevation or constant of capillarity of the water appears, accord- 

 ing to these experiments, to diminish. I imagine that this has 

 its explanation partly in the solution of the glass wall in the 

 distilled water. 



If we neglect the curvature of the walls, the elevation is pre- 

 cisely the constant a which was determined by Poisson. Assu- 

 ming the increase of the capillarity-constant given by Brunner* 

 for a diminution of temperature, we have thus for water, at 0°, 



a = 4*193 millims., a 2 = 17'58 sq. millims., a = 8'79 milligrms. 



The values of the constants are greater than those found by other 

 observers, because they allowed a longer interval to elapse be- 

 tween the formation and the measurement of the meniscus. 



14. The different values of the constant « are collected in the 

 following Table, and the substances are arranged according to 

 its magnitude. It must be understood that, except where I have 

 expressly mentioned the fact, all the substances were as pure as I 

 could obtain in commerce. 



* Pogg. Ann. vol. lxx. p. 515 (184/). 



