CHEMISTRY. 



75 



Elements when it does not contain a maximum of oxygen, the 

 0{ . termination of the genus is ite. Thus the salts which 

 P* try * contain sulphuric acid are called sulphates; those 

 ""~ Y " 1 which contain sulphurous acid are called sulphites. 

 This distinction is of some consequence, because the 

 gaits differ very much according as the acid is satu- 

 rated with oxygen or not. The ites are seldom per- 

 manent ; when exposed to the air, they usually at- 

 tract oxygen, and are converted into ates. 



Every particular species of salt is distinguished by 

 subjoining. to the generic term the name of its base. 

 Thus the salt composed of sulphuric acid and soda, 

 is called sulphate of soda. Triple salts are distinguish- 

 ed by subjoining the names of both the bases con- 

 nected by hyphens. Thus the salt composed of tar- 

 taric acid, potash, and soda, is called tartrate ofpot- 

 ash-and-soda. Sometimes, instead of this, one of the 

 bases it prefixed to the name by way of adjective. 

 Thus, soda muriate of rhodium means the triple salt 

 composed of muriatic acid, soda, and the oxide of 

 rhodium. Sometimes the name of the bapf prefixed 

 is altered a little ; as, ammonia-sulphate of magnesia 

 (sulphate of magnesia-aud-ammonia) ; ferruginous 

 sulphate of zinc (sulphate qfzinc-and-iron.) 



The salts naturally divide themselves into two clas- 

 ses. Those which contain an alkali or earth for their 

 base, derive their chief properties from the acids, and 

 are properly enough characterised by the name of the 

 acids applied to the names of the genera. But those 

 which nave for their base a metallic oxide, derive 

 their characteristic properties from that base, and 

 ought therefore to be arranged according to it. We 

 shall therefore divide this Chapter into two Sections ; 

 in the first, we shall treat of the salts with alkaline 

 and earthy bases ; in the second, of the salts with me- 

 tallic bases. 



SECT. I. Of Alkaline and Earthy Softs. 



Alkaline As the genera of these salts (derived from their 



and earthy acids) are very numerous, it will be advantageous to 

 tit*. th e learner, if we subdivide them into sets according 



to their properties. This is attempted in the follow- 

 ing Table. 



I. Incombustible Salts. 

 a. Not altered when heated with charcoal. 



1. Muriates. 



2. Fluates. 



3. Borates. 



4. Phosphates.* 



t. Decomposed without combustion when heated 

 with charcoal. 



1. Sulphates. 



2. Carbonates. 



e. Set fire to charcoal, or yield oxygen gas by heat. 



1. Nitrates. 



2. Nitrites. 



3. Hyper-oxymuriatea. 



4. Arseniates. 



5. Molybdatet. 



6. Tungttatet. 



Elements 



of 

 Chemistry. 



? Chromates. 

 8. Columbates. { 

 II. Combustible Salts. 



*. Acids partially dissipated by heat, leaving salts 

 in ate. 



1. Sulphites. 



2. Phosphites. 



b. Acids entirely dissipated by heat, leaving the 

 base and charcoal. 



-(-Acids partly sublimed unaltered. 



1. Acetates. 



2. Succinates. 



3. Moroxylates. 



4. Benzoates. 



5. Camphorates. 



+ -(-Acids wholly decomposed. 



6. Oxalatcs. 



7. Mellates. 



8. Tartratea. 



9. Citrates. 



10. Kinates. 



11. Saccolates. 



12. Urates. 



13. Sebates. 



14. Malates. 



15. Formiates. 



16. Suberatea. 



+ -f- + Anomalous. 



17. Gallates. 



18. Prussiates. 



Let us take a view of these genera in their order. 



GENUS I. Muriatet. 



The muriates are all soluble in water, and several Muriates, 

 of them likewise in alcohol. When mixed with sul- 

 phuric acid they effervesce, and white acrid fumes 

 with the odour of muriatic acid are exhaled. 



We are but imperfectly acquainted with these bo- 

 dies. Many of the compounds hitherto considered 

 as muriates, have been shewn by Mr Davy to be 

 compound:; of chlorine, and a metallic body. Thus 

 common salt is a compound of chlorine and sodium. 

 The following are the only salts which we know at 

 present to be muriates. 



Sp. 1. Muriate of Ammonia. This salt was named 

 sul ammoniac, because it was found native near the 

 temple of Jupiter Ammon in Africa. It is usually 

 in the form of hard elastic cakes. But by solution 

 and evaporation it may be obtained crystallized in 

 long four-sided pyramids. It deliquesces a little 

 when exposed to moist air. It is soluble in about 

 thrice its weight of water, and in about 75 parts of 

 alcohol. When heated, it sublimes without decom- 

 position, in a white smoke. 



Sp. 2. Muriate of Magnesia. This salt exists in 

 sea-water. It is not easily crystallized, but when its 

 solution, properly concentrated, is exposed to a sud- 

 den cold, it may be obtained in small needles. Its 

 taste is very bitter, hot, aid biting. It dissolves in 

 about half its weight of water, and in about twice 

 its weight of pure alcohol. When exposed to the 



The phosphates are decomposed when violently heated with charcoal, but the temperature required Is so high that the 

 decomposition cannot be effected in ordinary fires. Except the phosphate of ammonia, which is decomposed pretty earily. 



t The nitrate and hyperoxymuriate of ammonia are combustible alone. They are completely dissipated when heated. 

 The genera Im iulica arc placed from analogy onJy. 



