80 DISEASES CLAS* L 2. 2. 20. 



plate covers the aperture beneath, and is suspended by the ex- 

 panding sponge. This is removed every night and washed, and 

 returned into its place in the morning; on this account it is con- 

 venient to have five or six of them, for the sake of cleanliness. I 

 have been more particular in describing this invention, as I do 

 not know the name, or place of residence, of the maker. 



