4 1 6 Reflections on some iJincralogical Systems. 



salts, combustible minerals and metals. There are as man J 

 genera as chemical principles (clwmische bcstomdlheile) pre- 

 dominating in, or at least characterizing, the fossil combi- 

 nations. I know not what difference it is wished to make 

 between fundamental and chemical principles, and the 

 shades which separate them are not explained in a satisfac- 

 tory manner* Consequently I understand nothing of this 

 partition, in classes, genera^ 8cc. In the system of M. Hauy 

 there are four classes analogous to those of M. Werner ; 

 acicliferous substances, terreous substances, immetaliic com- 

 bustible substances, and metallic substances. In the first 

 class the alkaline and earthy nature constitutes the orders,- 

 and each individual base forms a genus. In the second 

 class here are no other snbdi visions than the species. The 

 third class contains two orders, the simple and compound 

 combustible^. Theifourth, three orders, according to the 

 voidability and reductabiiity of the metals, and each indivi- 

 dual metal forms a genus. All this is clear and precise, and 

 is not obscured by any superfluous explanations. 



XI. Werner has divided the chemical elements into two 

 functions in the classification of minerals. They are either 

 predominant in (juantitv or characterizing. In coppery py- 

 rites, iron is the most abundant principle; yet copper gives* 

 the character to the mineral. Chemistry accounts for the 

 abundance of a principle : yet the particular characters of a 

 fossil, its orvctognostic and other properties decide on its 

 characterizing power. But as all is drawn from the testi- 

 mony of our senses, and every thing is made to speak to 

 them in this system, the minerals in such a classification are 

 transported to the place which the characterizing principle 

 may assign them, however contradictory it should be to the 

 abundant principle. Thus 0M5 of silica prevails over 0*76 

 of alumine, and places spinelie in the siliceous genus, while 

 ()•£(> alumine against 046 silica transports the schist to the 

 argillaceous genus, and gives It its name. They have endea- 

 voured to explain the difference between the abundant prin- 

 ciple and the characterizing principle, by means of an en- 

 veloping matter {umbuUendcs sloffes) and the attempt has 

 had t lie success of most others for explaining that which we 

 do not understand ; it lias confined the difficulty to one 

 word. I shall not examine if this principle has been ob- 

 served in the distribution of minerals in genera, because- 

 this part of the classification is of little importance in com- 

 parison with that which treats of the species. It must how- 

 ever he observed, that it appears more and more every day 

 that we have gratuitously attributed to some elements the 



idea 



