in beer, being the growth of the eighth of an acre; one sheep, one-eighth of an ox, one third of a lamb, calf, and pig, being the produce of two acres; and in vegetables and fruits, the produce of the eighth of an acre.

Obs. Hence, every human inhabitant uses the produce of three acres; and the remainder of his share is consumed by horses; or engaged for buildings, roads, hedge-rows, or pleasure-grounds, or occupied in water.

62. Of the forty millions of cultivated land, twelve millions are employed in arable farming; twenty millions, in grazing cattle; two millions, in woods and hedge-roads; two millions, in roads, water, and buildings; and one million, in hop, garden, and pleasure-grounds; and the remainder lie in fallow.

Obs. The eight millions of waste consist chiefly of commons or heaths; and it is computed, that five millions of them are equal to any purpose of cultivation; the other three are in mountains; or have no depth of vegetable soil.

63. The number of bullocks killed, annually, in England and Wales, are at least a million; of sheep, nine millions; and of lambs, calves, and pigs, nine millions; besides thirty millions of poultry and game; and innumerable small birds and fishes.

The number of horses are nearly two millions; of which a million and a half are employed in agriculture and commerce.

Obs. It is calculated, that horses consume one-fifth of the entire produce of the land, i. e. the produce of four acres per horse on the whole of the land, or two acres each, of that 12 millions employed in raising corn.

64. On an average, each man, woman, and child, consumes ten ounces per day, of animal

food, or 220 lbs. in the year; which, in animal food, is the annual produce of two acres of land.

It is found, however, that the same two acres, cultivated in potatoes, would yield, on an average, upwards of ten tons per acre, or forty-four thousand pounds weight; and, consequently, afford one hundred and twenty pounds of potatoes, per, day the year round!

65. If cultivated in wheat, the produce of the same two acres, (which produce but 220 pounds of animal food,) would produce 4000 pounds weight of grain; or afford ten pounds of wheat, per day, leaving sufficient for seed.

Peas and beans yield in the same proportion. Turnips and carrots are as productive as potatoes! but parsnips actually double the weight of potatoes!

Obs. Mr. Middleton well observes, "that every acre would support its man well, on vegetable food; but," says he, "only let him change his diet to one meal per day of animal food; and he will require the produce of four acres!" The same author observes also, "that the starch or nourishment of a potatoe, is one-fourth of its entire weight; and that the quantity of starch or nutriment, on an acre of potatoes, is four times greater than in an acre of wheat." Those who seek further information on agricultural subjects, should consult Young's Farmer's Kalender; a work which ought to be found in every farm-house.

IV. Metallurgy.

66. Before man could till the ground, dig it, hoe it, or plough it, he required the aid of something harder than the ground itself; that is to say, he wanted iron or metals. Without iron, he

could have no very useful, sharp instrument ;such as the spade, hoe, plough, scythe, or sickle.

67. Hence, men were found to depend for food, on the spontaneous productions of the earth, and on the flesh of animals; till they had discovered the means of obtaining and working iron. Holy writ tells us that Tubal-cain (or Vulcan,) before the flood, was the instructor of all those who worked in brass and iron.

68. Viewing the metals in ordinary use, we consider them common productions; but no art is so curious, as that of extracting metals from the earth, or ore in which they are buried or concealand no discovery or invention was ever more wonderful.

ed;

69. It is very seldom that metals are found in a pure state; but perhaps the first discoverer, having found some metal in a detached or pure state, was led to make experiments on those lumps of shapeless, and coarse, but heavy earth; which consist of a mixture of earth and metal, and are called ores.

70. Gold-dust is frequently found in the sand of rivers; into which it is washed by the rains from the mountains. This itself might lead to the discovery of metals. Much of the gold used in England, is collected out of the rivers in Guinea, on the coast of Africa.

71. Workers of metals imitate nature when they beat and wash their ores; and having cleaned them, in that way, of much of the earth, they then burn them in various ways; and, at length, get the metal by itself in a pure state.

72. No one, on looking at most of the metallic

ores, would suspect them to contain meta!; they are, apparently, the roughest, coarsest, and least desirable stones or earths; but, on being broken, repeatedly washed, and burnt (or roasted, as it is called,) they yield Gold, Silver, Copper, Iron, and other metals.

73. These ores are found in the veins of mountains or in the strata, or divisions of rocks; generally beneath the surface of the ground; and the pits or wells, dug in search of the ore, are called mines. The well itself, is called the shaft of the mine. Pits, from which stone only is extracted, are called stone-quarries.

74. The deepest mines are in Hungary; and are about three-quarters of a mile below the surface. Many mines are like towns under ground; and many miners pass their whole lives in them. The want of fresh air, and the influx of water, prevent mines from sinking deeper.

75. All the substances which form the ground and earth, are called minerals. Clay is a mineral; all stones are minerals; coal is a mineral; chalk; and, in short, whatever is not animal or vegetable, is called Mineral.

76. The study of minerals has been methodized, and called the science of mineralogy. In this, as in many other branches of science, little more, however, has been effected, than to attain a systematic classification and nomenclature.

77. All minerals, i. e. all earths, soils, stones, and metals, are scientifically divided in four classes. I. Earthy Minerals-being all such, as are void of taste and smell, light and brittle; as mill

stone, flint or silex, clay, sand, chrystals, spar, gypsum, alabaster, chalk, stones, cornelians, jasper, topazes, sapphires, rubies, emeralds, and diamonds.

II. Saline Minerals-being such, as have a pungent taste, and are heavier, softer, and partly transparent; as salt, alum, nitre or salt-petre, borax, and alkali or potash.

III. Inflammable Minerals-being lighter, brittle, opaque, and never feeling cold; as coals, sulphur, black-lead, and amber.

IV. Metallic Minerals-being heavier, opaque, cold, and by proper processes may be reduced to their respective metallic states, as Gold, Silver, Copper, Iron, &c.

78. Many metals exposed to air become rusty; that is to say, they imbibe a part of the air called oxygen, and the rust is called an oxide. If melted and burnt on a fire for a considerable time, they also imbibe oxygen from the atmosphere; and turn into earthy substances, called oxides: the process is called oxidation.

79. If 10 lbs. of lead be melted and burnt in this manner, it will be converted into an oxide called red lead; and the red lead so produced, will be found to weigh 11 lbs., the additional pound arising from the imbibed oxygen.

80. Oxides may be converted into metals again, by depriving them of their oxygen. In the example of red lead, if it be burnt again with powdered charcoal, the charcoal will detach the oxygen from the oxide, and the lead will be obtained again in its pure state: this process is called reduction.