vl CONTENTS, 



CHAP. XVI. page 1 01. 



Compound Earths. 

 Definition of this Genus, Various compound Stones. 



CHAP. XVII. page 104. 

 Volcanic Produds. * 



Lava* Different Kinds,' Progrefs of a River of Lava. Compound 

 Parts of Lava. Pumice Stone. Bafaltes. Trapp. Terra Pux- 

 Kolana. 



CHAP. XVIII. page 109. 

 Metals. 



Ufes of Metals. Their Properties, Weight, Opacity, Malleability, 

 Duttility, Fujibility. Mix with each other.' Their Inflammability < 

 Calcinatien.~-Entire and Semi-metals. Perfeff and imperfel. 

 Natural Hiftory of Metals. Working of Mines. A/aying. 

 Smelting.- -Union with Acids. Attion of other Subjiances on Me- 

 tals. 



CHAP. XIX. page 120. 

 Arfenic. 



Natural Hi/lory of Arfenic. 'Mode of reducing it to the metallic Form. 

 White Enamel. Orpiment.~-Realgar. Its Ufe in Medicine . 

 A dreadful Poifon ; hoiu to detefi it in the Body. A Remedy for the 

 Poi/bn of Arfenic. 



CHAP. XX. page 1 24. 

 Molybdena. 



Short Account of this Semi-metal. May be reduced to an Acid. A 

 fcarce Mineral. 



CHAP. XXI. page 126. 

 Tungftein. 



TbeOreofTungftein confounded with that of Tin. Where found. 

 Mode of reducing it to the reguline or metallic State. 



CHAP. 



