Professor Necker on Mineralogy considered 



Order VI.—ACIDACEOUS. 



Chem. JV«/.— Free acids. 



Difficultly soluble in water, giving a red colour, when moist, to test paper 

 tinged with blue vegetable colours. 



Gen. — Arsenious acid ; boracic acid. 



Appendix Division — Crystals soluble in alcohol. 



Inflammable, soft and light. 

 ' Gen. Schererite (with Hatchetine ? and mountain tallow ?) 



To these will follow in our book two appendixes, one of crys- 

 talline minerals, not enough known in all their characters, to be 

 yet included in the classification ; the other of minerals not like- 

 ly ever to be found in a crystalline state, and being probably 

 groups of molecular individuals, either of only one genus, and 

 thus homogeneous in substance, or of more than one genus, and 

 therefore being heterogeneous or mixed minerals. 



If, instead, as we have done above, giving the pre-eminence 

 in doubtful cases to the physical characters over the considera- 

 tion of the chemical composition, we should have given the pre- 

 ference to this last consideration, the methodical arrangement 

 would have assumed in its highest divisions the form which we 

 are now to point out ; but then it would not have been a classi- 

 fication of natural history, as the heads of classification would 

 not have been positive characters belonging to individuals, but 

 mere abstract notions of a chemical nature. 



Division I. Substances containing no element supporting 



COMBUSTION. 



Corresponding to the Metallophanous, to some of the Amphiphan- 

 ouSf and to the Inflammable crystals. 



Sect. I. Inflammable metallic sttbstances, 



A. Simple metals ( Metallophanom Simple Metals), 12 genera normal. 



B. Compound combinations of simple metals (Metallophanous Alloys), 24 ge- 



nera normal. Total, 36 normal genera. 



Sect. II. Irjlammable metallic substances combined tviih not metallic 

 inflammable elements. 



A. Sulphurets (a Metallophanous Pyrites), 31 genera normal. 



(b Amphiphanous Sulfurideous), 6 genera anomalous. 



B. Carburets (Metallophanous Graphites), 2 genera normal. Total, 33 normal 



genera, G anomalous. 



