DOUBLE COMPOUNDS. 33 



always, has a very decided influence of this kind. 

 While acids and alkalies in their single blessedness 

 may be ever so dangerous, poisonous or corrosive, 

 they neutralize each other when combined, lose their 

 acidity, or acridity, and become the entirely or 

 comparatively harmless substances termed ''salts." 

 I do not flatter myself that the table of acids and 

 alkalies, or of the compounds (salts) which must 

 enter in consideration in a treatise on agricultural 

 chemistry, will afford as pleasant reading as many 

 of the modern novels; but I am sure that the young 

 farmer will flnd a thorough acquaintance with these 

 substances, with which he has to deal in his farming 

 operations, and some of which he finds mentioned 

 in almost every issue of the agricultural paper he 

 reads, far more pi:ofltable. The desire to know 

 " what things are made of " is universal. The toys 

 given to me during my childhood 



^°''^irsaite°''''^'* (^^^ ^^^^^ *^^s® presented to the 

 children of our neighbors) had to 

 suffer from my inquisitiveness, and they were in- 

 variably subjected to a mechanical analysis before 

 they had been in my hands many days. So it will 

 alway be a great satisfaction to any intelligent far- 

 mer to know the nature and composition of the 

 various substances which he has to handle. 



TABLE OF DOUBLE COMPOUNDS OR SALTS: 



forming carbon- 

 ate of lime. 



Ca^?>n^ [ forming carbonic acid 

 Calcfum [ ^^™^^^ ^^^^^'^^ 1™^ 



Carbfn}f^™^^g ^^^^^^^^ ^^^^ | forming carbon- 

 Oxygen \ 4.^^^- „ „^^„ f ate of soda. 



Sodium r°™''^S«°'^^ J 



