84 



on the outside, and then accumulating as the substance 

 sometimes rots. This is especially the case in Moss, when 

 it seems to have taken the entire figure of it. I add a spe- 

 cimen of the Moss ; but there are many varieties, some 

 even showing the species by the cast over it. Sometimes 

 the splashing of the water falling from a height heaps the 

 small grains on each other, and forms natural grottos. The 

 specimen Jigured leloiv, having been deposited in the place 

 of a nut kernel, is truly beautiful. I was favoured with it 

 from Knaresborough by the Rev. W. Danby, accompanied 

 by reflections upon it, such as the contrivances of Nature 

 generally excite in a truly enlightened mind. Lady Wilson 

 has lately brought me some granula of Carbonate of Lime 

 deposited in water used at Charlton House, which are very 

 small, resembling common sand, and which help to show 

 that Ketton Stone is merely a deposition of the same kind. 

 Is it the disturbing of the water, or any particular motion, 

 that might cause the Lime to form granules ? We have 

 great variety from this to the Botryoidal stones found in 

 Rutlandshire of a large size : — see tab. .284. 



