A tree is a swarm of individual plants; vegetables are either oviparous or viviparous; are all annual productions like many kinds of insects? Hybernacula, a new bark annually produced over the old one in trees and in some herbaceous plants, whence their roots seem end-bitten; all bulbous roots perish annually; experiment on a tulip-root; both the leaf-bulbs and the flower-bulbs are annually renewed. NOTE XV ... SOLAR VOLCANOS. The spots in the sun are cavities, some of them four thousand miles deep and many times as broad; internal parts of the sun are not in a state of combustion; volcanos visible in the sun; all the planets together are less than one six hundred and fiftieth part of the sun; planets were ejected from the sun by volcanos; many reasons shewing the probability of this hypothesis; Mr. Buffon's hypothesis that planets were struck off from the sun by comets; why no new planets are ejected from the sun; some comets and the georgium sidus may be of later date; Sun's matter decreased; Mr. Ludlam's opinion, that it is possible the moon might be projected from the earth. NOTE XVI ... CALCAREOUS EARTH. High mountains and deep mines replete with shells; the earth's nucleus covered with limestone; animals convert water into limestone; all the calcareous earth in the world formed in animal and vegetable bodies; solid parts of the earth increase; the water decreases; tops of calcareous mountains dissolved; whence spar, marbles, chalk, stalactites; whence alabaster, fluor, flint, granulated limestone, from solution of their angles, and by attrition; tupha deposited on moss; limestones from shells with animals in them; liver-stone from fresh- water muscles; calcareous earth from land-animals and vegetables, as marl; beds of marble softened by fire; whence Bath-stone contains lime as well as limestone. NOTE XVII ... MORASSES. The production of morasses from fallen woods; account by the Earl Cromartie of a new morass; morasses lose their salts by solution in water; then their iron; their vegetable acid is converted into marine, nitrous, and vitriolic acids; whence gypsum, alum, sulphur; into fluor- acid, whence fluor; into siliceous acid, whence flint, the sand of the sea, and other strata of siliceous sand and marl; some morasses ferment like new hay, and, subliming their phlogistic part, form coal-beds above and clay below, which are also produced by elutriation; shell-fish in some morasses, hence shells sometimes found on coals and over iron- stone. NOTE XVIII ... IRON Calciform ores; combustion of iron in vital air; steel from deprivation of vital air; welding; hardness; brittleness like Rupert's drops; specific levity; hardness and brittleness compared; steel tempered by its colours; modern production of iron, manganese, calamy; septaria of iron-stone ejected from volcanos; red-hot cannon balls.