[ xix ] 



and agats, we might ftill have feen whole col- 

 lections full of them with fuch imaginary 

 figures. 



Stones that are found in animals and fifhes, 

 are partly compounded of phlogifton, falts, and 

 a fmall quantity of earth, and partly coniift of 

 the fame matter with animal bones s and can 

 therefore with as little realbn have a place in a 

 mineral fyftem as the ftones of fruits. Soot, 

 tartar, yeaft, and things of fuch nature, have too 

 great affinity to the vegetable kingdom, and 

 are never to be met with under the iurface of 

 the earth ; wherefore they may in Botany be 

 confidered in the fame manner as regules, 

 glalTes, and flags are in Mineralogy. 



The hair-balls found in animals, and felt, 

 differ from one another in that the former a e 

 worked together by means of the periftaltic 

 motion in the bowels of the animals, and the 

 latter by the art of the feltmonger. May not 

 all thefe ftones of animals therefore be ranked 

 among the relief a animalia ? 



By all this it is very evident, that my chief 

 care has been to treat the mineral king- 

 dom in fuch a manner, that thole whofe 

 principal ftudy it is, may avoid every thing un- 

 neceffary and fuperfluous ; and by a perfect 

 knowledge of the fubjefts be brought to con- 

 fider hew to employ them to the bed advan- 

 tage ; whereby I hope that the pleafure of col- 

 lecting minerals will rather encreafe than be 

 difcouraged. If feme objects are thrown out 

 from mineral colle&ions on account they do 



b 2 not 



