MODE V. SMECTITE. 275 



MODE V. SMECTITE. 



This substance is commonly called fullers' 

 earth ; but as the latter word would here seem 

 rather a solecism, it may be preferable to adopt 

 the Greek denomination. 



Texture, earthy, sometimes with a very fine Characters, 

 grain. 



Hardness, cretic. Fracture, uneven, some- 

 times large conchoidal. Fragments, amorphous 

 and blunt. 



Weight, carbonose. 



Lustre, dull. Opake. 



The colour has often a greenish tinge, which 

 may arise from a very small portion of mag- 

 nesia; but as this scarcely amounts to 1 in 100, 

 there is no reason for classing it among the 

 Magnesian Rocks; especially as in that from the 

 island of Cimolus, which is superior even to the cimoiite. 

 English, Klaproth could discover no magnesia, 

 the unctuous feel arising from the mere purity 

 of the clay*. In general fullers' earth would Fullers' earth, 

 rather be judged of a light brown colour. The 



* Da Costa has observed that great fineness of the grain will 

 ften impart an unctuous feel. 



T 2 



