1886.1 



on Capillary Attraction. 



487 



of tlie rigidified water become fluid all over each of the surfaces 

 A and B ; you see exactly what takes place. The pieces of matter 

 I hold in my hands are not the supposed pieces of rigidified water. 

 They are glass, with the surfaces A and B thoroughly cleaned and 

 wetted all over each with a thin film of water. What you now see 

 taking place is the same as what would take place if things were 

 exactly according to our ideal suj^position. Imagine, therefore, that 

 these are really two ineces of water, all rigid, except the thin film 

 on each of the surfaces A and B, which are to be put together, 

 Eemember also that the Royal Institution, in which we are met, has 



Fig. 1. 



been, for the occasion, transported to the centre of the earth so that 

 we are not troubled in any w^ay by gravit}^ You see we are not 

 troubled by any trickling down of these liquid films — but I must 

 not say down, we have no up and down here. You see the liquid 

 film does not trickle along these surfaces towards the table, at least 

 you must imagine that it does not do so. I now turn one or both of 

 these pieces of matter till they are so nearly in contact all over the 



