SALTS. 



Triple Salts are those which have two bases united to one acid, 

 as the phosphate of soda and ammonia ; this may be regarded as two 

 phosphates combined, or as a phosphate of two bases ; some prefer 

 to call such combinations double salts. 



Neutral Salts were formerly regarded as those in which the pro- 

 perties of the acid and base are both entirely lost, as in sulphate of 

 potassa ; but sometimes there are peculiar characters imparted by 

 the acid or base, more commonly by the latter ; e. g. the salts of am- 

 monia are volatile ; of magnesia bitter ; of alumina styptic ; and of 

 glucina sweet. The nitrates are cooling, and they deflagrate with red 

 hot charcoal. In general, a salt is said to be insoluble, if it requires 

 1000 parts of water for its solution. 



Salts are not only compound bodies, but the acids and bases of 

 which they consist, are also compound. Thus, in sulphate of soda, 

 the acid is composed of oxygen and sulphur, and the base of oxygen 

 and sodium. It has been imagined by some, that in salts, the ele- 

 ments, losing the form of acids and bases, are directly united to 

 each other, so as to produce ternary or quaternary compounds. 

 Thus, in sulphate of soda, the oxygen, which exists in the acid, in 

 the base, and in the water of crystallization ; the sulphur of the acid ; 

 the sodium of the base, and the hydrogen of the water, are regarded 

 as being in immediate union, to form a quaternary compound; 

 but of the truth of this speculation there is no direct proof; and 

 it is extremely improbable that it is true, because the acid, the base 

 and the water can be combined synthetically, to form the salt ; 

 the water can be expelled by heat and recovered, and the galvanic 

 power will separate the acid and alkali unaltered, in full proportion, 

 and we know not of any affinity which should unite^these bodies in 

 a quaternary combination, and then resolve them again into binary 

 compounds. 



NOMENCLATURE AND CHARACTER OF SALTS. 



1. As almost every acid unites with nearly every base, and some- 

 times in more than one proportion, it follows that the salts are very 

 numerous. 



2. They are said to exceed 2000, although not more than thirty 

 were known fifty years ago. 



3. The old names were sometimes barbarous, absurd, or false, im- 

 plying incorrect ideas. 



4. The nomenclature of the French chemists,* is eminently use- 

 ful in the study of the salts. 



5. Every salt consists of an acid and a salifiable base, and the 

 bases, except ammonia, are all oxides of metals or of inflammable 

 bodies. 



* See page 35. 



