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4-6° Tbird Appendix. luble, and with effervefcence, in fpirit of nitre 1,10. 4th, Thofe that are foluble in fpirit of nitre, in the temperature of the atmofphere, but with- out effervefcence. 5th, Thofe that are foluble in the nitrous acid, without effervefcence, but only in the tempera ture of from 150° to 180 0 , or higher. 6th, Thofe that do not effervelce with the ni trous, but effervefee flightly with the concen- trated vitriolic acid. 7th, Thofe that are infoluble both in the ni. trous and vitriolic acid, or only very flightly fo luble, and with little or no effervefcence, yvithout particular management. Before earths or flones are fubjedted to this teil they fhould be reduced to powder. Earths in particular fhould be boiled in fixteen times their weight of water, to dilcover their faline contents; diltilled to difcover their volatile ingredients, and gradually heated to rednefs in a covered, and afterwards to whitenef3 in an open crucible for half an hour, to obferve their change of colour and lofs of weight; both, as circumftances in* dicate, may be projeäed on melted nitre heated to rednefs, to difcover whether they contain the carbonaceous principle. In the prefent ftate of mineralogical know- ledge, analyfis is become an objedt of complica- ted attention, as notice muft be taken of the nine earths^ already enumerated ;—five acids, namely, the vitriolic, marine, fparry, phofphoric, and boracic;—five metallic fubfiances, iron, manga- nefe, nickel, cobalt, and copper.—Not that all thefe are ever found in any compound, but, it being uncertain which of them may occur, none