180 NATURAL HISTORY. 



very close ; so that when the neck of the bladder 

 drieth, no air may possibly get in nor out. Then 

 bury it three or four foot under the earth in a vault, 

 or in a conservatory of snow, the snow being made 

 hollow about the bladder, and after some fortnight s 

 distance, see whether the bladder be shrunk ; for if 

 it be, then it is plain that the coldness of the earth 

 or snow hath condensed the air, and brought it a 

 degree nearer to water : which is an experiment of 

 great consequence. 



Experiment solitary touching congealing of water 

 into crystal. 



36 1. Itis a report of some good credit, that in deep 

 caves there are pensile crystals, and degrees of crys 

 tal that drop from above, and in some other, though 

 more rarely, that rise from below : which though it 

 be chiefly the work of cold, yet it may be that water 

 that passeth through the earth, gathereth a nature 

 more clammy, and fitter to congeal and become solid 

 than water of itself. Therefore trial would be made, 

 to lay a heap of earth, in great frosts, upon a hollow 

 vessel, putting a canvas between, that it falleth not 

 in : and pour water upon it, in such quantity as will 

 be sure to soak through, and see whether it will not 

 make an harder ice in the bottom of the vessel, and 

 less apt to dissolve than ordinarily. I suppose also 

 that if you make the earth narrower at the bottom 

 than at the top, in fashion of a sugar-loaf reversed, 

 it will help the experiment. For it will make the 

 ice, where it issueth, less in bulk, and evermore 

 smallness of quantity is a help to version. 



