LECTURE XIX. _Of Solid Substances_ 76 _Of Calcareous Earth_ 77 _Of Siliceous Earth_ 79 LECTURE XX. _Of Argillaceous Earth_ 81 _Of Terra Ponderosa_ 82 _Of Magnesia_ 83 LECTURE XXI. _Of Ores_ 84 _Of Gold_ 87 LECTURE XXII. _Of Silver_ 90 _Of Platina_ 92 LECTURE XXIII. _Of Mercury_ 94 LECTURE XXIV. _Of Lead_ 99 _Of Copper_ 101 LECTURE XXV. _Of Iron_ 105 LECTURE XXVI. _Of Tin_ 109 _Of the Semi-metals_ 113 LECTURE XXVII. _Of Nickel_ 115 _Of Arsenic_ 116 _Of Cobalt_ 118 _Of Zinc_ 119 LECTURE XXVIII. _Of Antimony_ 121 _Of Manganese_ 123 _Of Wolfram_ 124 _Of Molybdena_ 125 _Of Solid Combustible Substances_ 126 LECTURE XXIX. _Of the Doctrine of Phlogiston and the Composition of Water_ 127 LECTURE XXX. _Of Heat_ 135 LECTURE XXXI. _Of Animal Heat_ 145 LECTURE XXXII. _Of Light_ 148 LECTURE XXXIII. _Of Magnetism_ 155 LECTURE XXXIV. _Of Electricity_ 162 LECTURE XXXV. _The same Subject continued_ 170 LECTURE XXXVI. _The same Subject continued_ 177 LECTURES ON EXPERIMENTAL PHILOSOPHY. LECTURE I. _The Introduction._