50 



which gypsum is formed, from a well just dug in Cambridge. 

 It is continually crystallizing from tli& sulphur of pyrites 

 and oyster shells at Shotover Hill-, near Oxford. 



The lower Jlgure is on a piece of limestone with a foetid 

 odour, called stinkstone, the gypsum spreading in a very 

 peculiar manner on the surfaces in patches. I was favoured 

 with this from the neighbourhood of Durham, by the Rev. 

 John Harriman. 



