Volume I Part 16 (1/2)

Discovery of fire. Tools of steel. Forests subdued. Quant.i.ty 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

Acc.u.mulation of electricity not from friction 335

Mr. Bennet's sensible electrometer 345

Halo of saints is pictorial language 358

We have a sense adapted to perceive heat but not electricity 365

Paralytic limbs move by electric influence 367

Death of Professor Richman by electricity 373

Lightning drawn from the clouds. How to be safe in thunder storms 383

Animal heat from air in respiration. Perpetual necessity of respiration.

Spirit of animation perpetually renewed 401

Cupid rises from the egg of night. Mrs. Cosway's painting of this subject 413

Western-winds. Their origin. Warmer than south-winds. Produce a thaw 430

Water expands in freezing. Destroys succulent plants, not resinous ones.

Trees in valleys more liable to injury. Fig-trees bent to the ground in winter 439

Buds and bulbs are the winter cradle of the plant. Defended from frost and from insects. Tulip produces one flower-bulb and several leaf-bulbs, and perishes. 460

Matter of heat is different from light. Vegetables blanched by exclusion of light. Turn the upper surface of their leaves to the light. Water decomposed as it escapes from their pores. Hence vegetables purify air in the day time only. 462

Electricity forwards the growth of plants. Silk-worms electrised spin sooner. Water decomposed in vegetables, and by electricity 463

Sympathetic inks which appear by heat, and disappear in the cold. Made from cobalt 487