7.9 Punyah etc.  By its own  nature  pure is that smell which exists in the earth as its exclusive property.  The foulness, the excessiveness [of th smell]  are due to  contamination of  other elements.  That has been stated  [elsewhere] as :
 
'[A  particular  thing]  becomes hard because of the excess of the properties  of the earth;  foul-smelling on account of the rise of the  fire-properties;  and stiff due to liberality  (excess)  of the properties of water'  and  so on.