MINERALOGY. 113 



CLASS II. 

 WATER-EARTHS. SALTS. 



541. The chief distinctions of the salts consist also in 

 their combination with the other classes, and we have 

 therefore 4 orders 



1. Earth-Salts . . . Double-salts. 



2. Saline-Salts . . . Neutral-salts. 



3. Inflammable-Salts . Saponaceous-compounds. 



4. Metallic-Salts . . Vitriols. 



The same will hold good without doubt of the orders, as 

 in the case of the earths. They form as many families 

 as there are principal masses of them present, with which 

 they may combine. As the acids, from being the children 

 or offspring of water, play the chief part in the water 

 minerals, and are themselves nothing else than oxydized 

 and outwardly lying masses, they carry consequently 

 within themselves the number and import of the families ; 

 thus it is they which determine indeed the division. If 

 the bases were to be taken as the groundwork of 

 arrangement, there would be only earths and alkalies, 

 and on the other hand numerous metals, by which step 

 the mineralogist would fall into the unprincipled method 

 of classification adopted by empirics. Here also the 

 philosophy of nature shows, and that indeed upon sound 

 reasoning, that the acids and not the bases afford the 

 principle of a natural classification. A somewhat differ- 

 ent opinion is held by the chemist, who must charac- 

 terize the salts according to both series ; but this is by no 

 means the course taken by the historian of nature. 



ORDER I. 



Earth-SaltsDouble Salts. 

 (Combinations of acids with earths.) 



Earn. 1 4. Earthy-acids or Eluoric-acid earths; here also belong Bromic, lodic, 



and Cyanic acids. 



5. Salt or Boracic-acid. 



6. Inflammable or Sulphuric-acid Alum, Sulphate of magnesia. 



7. Metallic or Arsenic-acid. 



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