270 



M. Beudant on the Connexion between 



[April, 



Copper pyrites 



Sulphuret of copper . 



Antimoniated sulpliu- 

 ret of lilver 



Sulphuret of antimony. 

 Sulphur ? 



Metallic copper . 

 Sulphuret of zinc, 



Silver and manganese. . 

 Loss. 



St. Wen z el. 



21224 



24-221 



22-273 



29-232 

 1-3 



, 6-506 

 7-000 

 7-718 

 18-994 

 5-227 

 13250 

 5-368 

 3-655 

 <Ant.21-632 

 ?Sul. 7-600 



ZlLLA. 



1-750 



100- 



19-708 



17-236 



5-042 



37 562 



17-740 



2-500 



6-042 

 6-500 

 1-166 



13-506 

 3730 

 3-000 

 1-215 

 0-827 



27-785 

 9-777 



100- 



Kapnick. 



29-743 / 

 5-556 



fSul. 

 6-562 -Jof z. 



(Sul. 

 0-250 

 3-750 



3-021 

 3250 

 3-583 

 34-729 

 9-556 



22-000 



7-713 



} 



5000 

 1-562 



100- 



But as the crystalline form of the mixture is that of the copper 

 pyrites only, we may arrange it first under that species ; and as 

 the specimen described in the first column does not contain a 

 notable excess of any other compound, it may stand with the 

 Copper pyrites only ; the specimen in the second column may, 

 according to the rule proposed, be arranged also under the 

 s.ulphuret of antimony, from the large proportion of that substance 

 contained in it ; and the third specimen, for the same reason,. 

 may be placed also with the copper pyrites. 



The author has preferred borrowing an illustrative example of 

 the system of classification he has suggested, from the species 

 grey copper, because that substance admitted the closest appli- 

 cation of his reasoning : but as the tetrahedral form may apply 

 to many other compounds, it is impossible, at present, to say, 

 decidedly, that it is derived from the copper pyrites in the 

 instance under consideration ; and although it was the opinion 

 of Rome Delisle that it was so derived, the author thinks it 

 safer still to continue the grey copper as a separate species. 



It would be possible to produce other examples of mineral 

 mixtures capable of the same kind of analysis, but the number 

 is very limited. Of the combinations of the elements of the 

 greater part, and particularly of the earthy substances, we know 

 nothing ; and we learn from analysis only the elements of com- 

 pound bodies, and not the different species that constitute the 

 compound. Hence, although the results of analysis may lead 

 us to infer a mixture in the body we examine, chemistry, in its 

 present state, cannot discriminate its extraneous from its ele- 

 mentary principles. 



The mineralogist will, therefore, proceed with greater certainty 

 by adopting the single classification founded on the crystalline 



