substantial grounds, than on the principle 

 of warmth communicated by friction ; for 

 where the water flows with rapidity, you 

 of course use or filter twice as much as 

 you do, on the same quantity of surface, 

 where it moves sluggishly ; and if there 

 is any thing substantial to be thus col- 

 lected from the water, two tons of water 

 will doubtless afford more substance, or 

 sediment, than one can give. 



Mr. B., in continuation, adds, p. 11, 

 " And although the water is so exceeding 

 " clear, yet upon its being thrown over 

 " the land, only for a few days in warni 

 " weather, by dribbling through the grass, 

 " so thick a scum will arise, and adhere 

 " to the blades of the grass, as will be 

 " equal to a considerable quantity of ma- 

 " nure spread over the land, and (it may 



" be 



