more sugar, extract, and tannin, provided they be in- 

 timately combined with the other principles of the 

 compound. 



The mode of separating starch is similar to that 

 of separating mucilage. 



If after the action of hot water any thing remain, 

 the action of boiling alcohol is then to be tried. This 

 will dissolve resinous matter ; the quantity of which 

 may be known by evaporating the alcohol. 



The last agent that may be applied is ether, 

 which dissolves elastic gum, though the application is 

 scarcely ever necessary ; for if this principle be pre- 

 sent, it may be easily detected by its peculiar qualities. 



If any fixed oil or wax exist in the vegetable 

 substance, it will separate during the process of boil- 

 ing in water, and may be collected. Any substance 

 not acted upon by water, alcohol, or ether, must be 

 regarded as woody fibre. 



If volatile oils exist in any vegetable substances, 

 it is evident they may be procured, and their quantity 

 ascertained, by distillation. 



When the quantity of fixed saline, alkaline, met- 

 allic, or earthy matter in any vegetable compound is 

 to be ascertained, the compound must be decomposed 

 by heat, by exposing it. if a fixed substance, in a cru- 

 cible, to a long continued red heat j and if a vola- 

 tile substance, by passing it through an ignited porce- 

 lain tube. The nature of the matter so produced, 

 may be learnt by applying the tests mentioned in 

 page 103. 



