CHEMICAL HISTORY OF A CANDLE *7 



the fluid, that you may see the action better.) You observe 

 that, now I pour in the fluid, it rises and gradually creeps up 

 the salt higher and higher; and provided the column does 

 not tumble over, it will go to the top. If this blue solution 

 were combustible, and we were 

 to place a wick at the top of 

 the salt, it would burn as it 

 entered into the wick. It is 

 a most curious thing to see 

 this kind of action taking place, 

 and to observe how singular 

 some of the circumstances are 

 about it. When you wash your 

 hands, you take a towel to 

 wipe off the water; and it is FlG - ss 



by that kind of wetting, or that kind of attraction which 

 makes the towel become wet with water, that the wick 

 is made wet with the tallow. I have known some care- 

 less boys and girls (indeed, I have known it happen to 

 careful people as well) who, having washed their hands 

 and wiped them with a towel, have thrown the towel over 

 the side of the basin, and before long it has drawn all the 

 water out of the basin and conveyed it to the floor, because it 

 happened to be thrown over the side in such a way as to 

 serve the purpose of a siphon. ( 5 ) That you may the better 

 see the way in which the substances act one upon another, I 

 have here a vessel made of wire gauze filled with water, and 

 you may compare it in its action to the cotton in one respect, 

 or to a piece of calico in the other. In fact, wicks are some- 

 times made of a kind of wire gauze. You will observe that 

 this vessel is a porous thing; for if I pour a little water on 

 to the top, it will run out at the bottom. You would be puz- 

 zled for a good while if I asked you what the state of this 

 vessel is, what is inside it, and why it is there? The vessel 

 is full of water, and yet you see the water goes in and runs 

 out as if it were empty. In order to prove this to you I have 



8 The late Duke of Sussex was, we believe, the first to show that a prawn 

 might be washed upon this principle. If the tail, after pulling off the fan 

 part, be placed in a tumbler of water, and the head be allowed to hang over 

 the outside, the water will be sucked up the tail by capillary attraction, and 

 will continue to run out through the head until the water in the glass haft 

 sunk so low that the tail ceases to dip into it. 



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