ON A NATURAL SYSTEM 



genitive of their bafc. The fourth contains the 

 triple falts and thofe of fcveral principles, which 

 are exprefled by the trivial names ; and as in 

 them we neither find the adjecYive- of the bafe 

 atits, nor the genitive, it is not pofliblc that any 

 ambiguity can arife. The whole compofition of 

 the triple falts could not be fignified in two 

 words, unlcfs the double falts were defined in 

 one only ; and if the fame brevity were expect- 

 ed of the quadruple, the triple mud have necef- 

 farily been denominated by one. But it may be 

 a queftion, whether it is more difficult to invent 

 fuch a number of new and fimple names, or, if 

 invented, whether they could poflibly be retain- 

 ed by tlu memory. 



c x c v 1 1 . Of tbf fpecific Na mes of Ea rtbs, Me- 

 tah\ and Pbhgijlic Sub/lancet. 



IF we confider every thing that has been faid 

 in the foregoing lections on the fubjccl of the 

 falts hitherto known and inveftigatcd, we fliall 

 find, that we have in fome mcafurc laid the 

 foundation of a general fydemof mineralogy. 

 With regard to the earths, and the following 

 clafTes, the denomination of the double and 

 more compounded ipccies may be conveniently 

 expreflcd by the trivial names in two words. 

 Thus, for example, under the genus magnefia, 

 a fpecies occur, in the formula, finca, compofcd 



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