258 SIR DAVID BREWSTER'S EXPERIMENTS. 



in which he treats of capillary attraction, as a 

 modification of chemical affinity. 



That this is really the case, would appear from 

 various considerations : 



1. Capillarity is the force by which liquids 

 and solids are made to cohere, whether homoge- 

 neous or heterogeneous. 



2. Every solution of a solid in a liquid, is the 

 result of a chemical force, by which their par- 

 ticles are united. 



3. The force of capillary attraction, by which 

 liquids permeate solids, is always in proportion 

 to their chemical affinity for each other for ex- 

 ample, water has a strong affinity for sugar. It 

 also rises rapidly through it by capillary attraction. 



Considering the vast importance of the subject, 

 it is really surprising how imperfect and limited 

 the number of experiments that have been in- 

 stituted for the purpose of elucidating its nature. 

 Sir David Brewster has given the relative heights 

 to which fifty-two different liquids rose through 

 a capillary glass tube, the bore of which was 

 0,0561 of an inch the general result of which 

 was, that water rose to a greater height than any 

 other liquid. The next in order were muriatic, 

 nitric, and nitrous acids ; then the volatile oils ; 

 after which were alcohol and the aethers; and 

 lastly, sulphuric acid.* But if capillary attrac- 

 tion represent the force by which all liquids and 

 solids cohere, it is obvious, that before we can 



* Edinburgh Encyclopaedia, Article Capillary Attraction. 



