Electric Eel. Its electric organs. Compared to the electric Leyden phial 202

Discovery of fire. Tools of steel. Forests subdued. Quantity of food increased by cookery 212

Medusa originally an hieroglyphic of divine wisdom 218

Cause of explosions from combined heat. Heat given out from air in respiration. Oxygene looses less heat when converted into nitrous acid than in any other of its combinations 226

Sparks from the collision of flints are electric. From the collision of flint and steel are from the combustion of the steel 229

Gunpowder described by Bacon. Its power. Should be lighted in the centre. A new kind of it. Levels the weak and strong 242

Steam-engine invented by Savery. Improved by Newcomen. Perfected by Watt and Boulton 254

Divine benevolence. The parts of nature not of equal excellence 278

Mr. Boulton's steam-engine for the purpose of coining would save many lives from the executioner 281

Labours of Hercules of great antiquity. Pillars of Hercules. Surface of the Mediteranean lower than the Atlantic. Abyla and Calpe. Flood of Deucalion 297