PECULIAR FOG IN ICELAND. 161 



structure of bodies. I will say only that most liquids 

 have a marked disposition to take this form, and that it 

 appears to be the result of their viscosity or mutual 

 attraction of their elementary parts and of the figure 

 proper to those parts ; it is a kind of crystallization — the 

 degree which water is capable of whilst it retains sufficient 

 heat to be fluid/' 



The conclusions drawn by Saussure are quite unwar- 

 ranted by his observations ; and one can scarcely find 

 anywhere that he sees any thing that would lead him to 

 consider the particles hollow. It is a vague inference 

 from certain of their qualities and their supposed analogy 

 to soap-bubbles. 



I have tried his few experiments, and think he may be 

 right about the size of the granules he speaks of when 

 water condenses in a bulb ; but as to their vesicularity, I 

 consider he has no right to pronounce an opinion in this 

 case. If vesicularity be proved, it must be by larger 

 powers than he has used, or by better eyes than he pre- 

 tended to have. If there are vesicles formed by con- 

 densation, they are still to find. And this will apply 

 either to the vapour in the glass bulb or the atmosphere 

 above us. 



When vapour rises from water which is heated,,or, let us 

 say, in ebullition — on bubbling, from whatever cause, the 

 result maybe different. If steam aises a bubble of water, 

 it may take it into the air, and on cooling leave a little 

 air which it may have received from the water. The 

 amount in this case will be excessively small ; but I do 

 not know that it has ever been observed. If, however, 

 gas should be present in greater quantities than the air in 

 water, we may expect a larger bubble to remain formed 

 for a while. This is especially the case when hydrogen 

 bubbles out of an acid solution where zinc or iron is dis- 

 solving. It seems to form small balloons which carry the 



SER. III. vol. v. M 



