CHARACTERS 



OF THE 



CLASSES, ORDERS, GENERA, 

 AND SPECIES. 



CHARACTERS OF THE CLASSES. 



CLASS I. 



G. under 3-8. 

 No bituminous odour. 

 Solid : taste. 



CLASS II. 



G. above 1-8. 

 Tasteless. 



CLASS III. 



G. under 1-8. 



Fluid : bituminous odour. 

 Solid : no taste. 



