SALMON — ON ROCKS. 



53 



List of Elements and Binary Compounds, either being themselves 



ROCK-FORMIXG MINERALS, OR FORMING CONSTITUENTS OF ROCK- 



FORMiNG Minerals. 

 Those marked with an asterisk (*) are mzne^-a^.s,— thatis, occur naturally ; those 

 with a double asterisk (**), abundantly. The others form the chemical consti- 

 tuents of minerals, but are not minerals themselves. 



Chemical 

 Symbol. 



Abbreviated 

 Mineralogical 

 Symbol. 



**Carbon 

 '^'Sulphur 



3. Water . 



4. * Alumina 



5. Lime . 



6. * Magnesia 



7. Baryta . 



8. Potash . . 



9. Soda . . . 



10. Lithia . . 



11. '"-^Silicic Acid 



12. Carbonic Acid 



13. Sulphuric Acid 



14. '"Boracic Acid . . 



15. ''''^Sesqui-oxide Irou 



16. Protoxide Iron . 



17. *Sesqui-oxide Manganese 



18. Protoxide Manganese. 



19. ''-'"Chloride Sodium . 



20. '"Fluoride Calcium . 



21. *Bi-Sulphide Iron . 



<1 



o 



Carbonic and Sulphuric acids also occur naturally in volcanic regions, in the 

 -form of gases. Lime, Magnesia, and Baryta are also called Alcaline Earths. 



XIV. Of the elementary bodies it therefore appears that only two 

 — carbon and sulphur — are found as minerals in any considerable 

 quantity. In composition they are unimportant in rocks, except in 

 the binary compounds given. 



Of the binary compounds also there are proportionately few which, 

 directly as minerals, have an important share in the formation of the 



