16 POTASH. 



The organic part of plants, although so much the 

 larger, consists at most of four substances; but in the 

 ash, we occasionally find as many as ten. These are 

 named as follows : Potash, Soda, Lime, Magnesia, 

 Oxide of Iron, Oxide of Manganese, Silica, Chlorine, 

 Sulphuric Jlcid (oil of vitriol), and Phosphoric Jlcid. 



Here is a list of what may seem very hard names, 

 but neither the farmer nor the scholar must be fright 

 ened at them : when he has once seen the substances 

 to which they belong, and has learned by experience 

 their more important properties, he will perceive that 

 he is really able to comprehend something about them, 

 and will at once recover from the feeling of dread and 

 aversion which they at first excited. There may be 

 some consolation, too, in the knowledge that the above 

 list comprises the greater portion of the new words 

 which will be employed in the succeeding chapters of 

 this little work. We will then now commence with 

 good courage, and notice each of these inorganic 

 substances separately. 



Potash is well known as the extract by water from 

 3y^? wood ashes, boiled down to dryness. a. It attracts 

 == :=r moisture from the air when strong, and, if touched to 

 - f\ the tongue, causes an acrid burning sensation called 

 / L by chemists an alkaline taste: it is often strong enough 

 4 y ( to destroy the skin, and may be purified to such a 

 -~- ' strength as to corrode almost every perishable sub 

 stance. 6. When purified in the ordinary way, potash 

 forms pearlash, which is simply potash deprived of the 

 foreign bodies with which it was contaminated, and 

 carbonated or combined with carbonic acid : in this 

 state it is nearly white, c. Potash is quite abundant 

 h in plants : more so in some classes than others. It is 

 u injurious to some kinds of weeds, or at least >s used 

 ^ Ji to extirpate them by bringing in better kinds. 



