274 



SALTS. 



CHAPTER III. 



SALTS. 



SOLUTION AND CRYSTALLIZATION. 

 , 685. DEFINITION. Under the general 



What com- 

 pounds are head of salts, are included all compounds 



of acids and bases, and beside these, the 

 compounds of chlorine, bromine, iodine, sulphur, &c. 

 with the metals. Sulphate of soda, or blue vitriol, is 

 an example of the first class, and chloride of sodium, 

 a common salt, of the latter. 



686. PREPARATION or SALTS. The salts 



Mention some 



methodsofpre- of most acids may be produced, by sim- 



paring salts ? ^ b rmgmg tne ac id an d ox id e together. 



Sulphate of potassa is thus produced, from sulphuric 

 acid and potassa. Heat is sometimes required, to bring 

 about the combination. They may also be prepared 

 from the carbonates. Thus acetate of lime, is pro- 

 duced by pouring strong vinegar on chalk, or carbo- 

 nate of lime. Carbonic acid is, in such cases, expelled 

 by the stronger acid which is employed. Other meth- 

 ods of preparing individual salts, will be hereafter 

 given. 



Explain solu- 687. SOLUTION. The particles of all 

 tion. bodies are held together, as before ex- 



plained, by the attraction of cohesion. But water has 



