INTRODUCTION. coals, building ftones, faline fubflances, &c. ory&og- noftic knowledge is abfolutely neceffary; without it they will be expofed to perpetual Ioffes and difap- pointments. Tf 'nof ^' >e man ^ era ^ education it will afford much liberal fcdu- inflruction and pleafure. It will give him a very wtfou. g re at degree of accuracy in the determination of the external afpe&s of bodies, whether natural or artifi cial, and this precifion he will carry into the other objects of his enquiries. Befides this, by be coming acquainted with the materials of which the earth is compofed, he will naturally be led to conti nue his refearches in order to become acquainted with thofe more extenfive relations of minerals which are made known to us by that fublime branch of mineralogy Geognofie. Qualifies- 15. 1 o be entitled, however, to the chara&er of an ed of an oryclognpft,that empyrical knowledge which we fo of- noit. K * en mee t with will not fuffice. To merit fuch a name we muff be fully acquainted with all the external charadlers, with the^manner of employing them ; we muff have a readinefs in knowing and a precifion in difcriminating minerals; we muff be able eafily to refer known minerals to their place in the fyftem, and when new fpecies or fubfpecies occur, we muff be able to give them their proper place in a natural arrangement, and to arrange the tranfitions in fuch a manner that the mineral fpecies or fubfpecies may participate of the chambers of the preceding and the following members of the fyftem. We muff from well eholen fpeejmens be able to determine the na ture