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 potu toes! but parsnips actually double the weight of potatoes!

Obs.-Mr, Middleton well abserves," 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 observo, 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 infor mation on agricultural subjects, should consult Foung's Farmer's Kalendar; 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, till they had discovered the means of obtaining and working iron, men were found to depend for food, on the spontaneous produc fions of the earth, and on the flesh of animals, Holy writ tells us that Tubal-cain (or Vul can), was the instructor of all those who, before the floud, worked in brass and iron.

66. 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 concealed; and no discovery or invention. was ever more wonderful.

69. Metals are very seldom 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 which are called ores.

70. Gold-dust is frequently found in the sand of rivers; whither 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 cleared 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 metal: they are, apparently, the roughest, coarsest, and least desirable stones, or earths; but, on being broken, repeatedly washed, and burnt, (or, reasted, as ibis called,) they yield Gold, Silver, Copper, Iron, and other nietals.

75. These ores are found in the veins of mountains, or between the struta, 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 extructed, are called stonequarries.

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.

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

76. The study of minerals has been metho dised, 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 into four

classes.

1. Earthy Minerals--being all such, as are void of taste and smell, light and brittle; as millstone, dint or silex, clay, sand, etystuls, spar, gypsum, alabaster, chalk, stones, cornelians, jasper, topazes, sapphires, tubies, emeralds, and dinnionds.

II. Saline Minerals-being such, as have a

pungent taste, and are heavier, softer, and . partly transparent; as common salt, alum, nitre or salt-petre, and borax.

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, ductile, capable of being drawn into wire, and malleable, capable of being worked into shape. These consist of gold, sil ver, &c.; see paragraph, 522, for other particulars.

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

79. If 10 lbs. of lead be melted and heated 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.

81. Modern chemists consider the whole earth as metallic; and all the different earths to be

nothing more than various oxides, or rusts of metals, produced by the continued action of the air and water on them; and capable, by suita

ble means, of being reconverted into metals!

82. Platina is the heaviest of all metals, being 23 times heavier than water; but it is a modern discovery. The colour is light grey, and it cannot be melted in ordinary fires.

83. Gold is 19 times heavier than water; and the most valuable of all the metals. It is so malleable, that an ounce of it will gild a silver wire 13,000 miles in length; and it may be beaten into leaves; 300,000 of which, are only the thickness of an inch.

84. Silver is 11 times heavier than water; and next to gold in beauty; such is its ductility, that it may be drawn out in wire finer than a hair,

85. Mercury, or Quicksilver, is 14 times heavier than water; and is remarkable for being liquid like water; and for not becoming solid except in cold greater than that which renders water solid.

86. Copper is 9 times heavier than water; and is found in great abundance in the mines in Sweden, and also in the isle of Anglesey. Ir unites well with other metals; and forms a yariety of useful compounds.

37. Iron is 8 times heavier than water; and is the most useful, and, in England, the most abundant of all the metals. It mixes with the animal, vegetable, and mineral kingdon. It is melted with more difficulty than gold, silver, or copper; and it usefully strikes fire with flint.