fied granite had been formed; disturbing forces had broken the rocks in fissures or rents, and formed receptacles for the various metals, so important to man.

We may ask the question, Whence come those metals? Very probably from the great laboratory in the interior of the earth, where immense heat, operating on materials unknown to man, formed them, and drove them upwards into receptacles in the cloven rocks, as into magazines and treasuries for the future use of man. In these depositories of nature are found veins of iron, copper, arsenic, silver, and gold, which may be traced to the underlying granite.

Metallic veins are most frequently found in rocks of the primary and transition periods, especially in the lower portions of stratified rocks which are nearest to the unstratified crystalline rocks. Metallic veins become scarce. in the more recent periods. In the situations in which they are found they are accessible, but very commonly require labor.

The elaboration of iron ore was very abundant in all parts of the globe, far more so than any other of the metals. The importance of iron to man is well understood; for man alone can use it; and it is a clear indication that God, in his

wisdom and goodness, in those remote ages, was preparing for the comfort and happiness of his favorite creature, man. Such is the importance of iron to the human race, that civilization without it would be nearly impossible.

The natives of Mexico and Peru were probably as far advanced as possible in civilization without iron. Yet, even allowing the glowing descriptions of the Spaniards who conquered the country, they were immensely below those nations who had discovered the use of iron.

Gold and silver may serve as stimulants to industry, but cannot be made the implements of power. Gold stimulates men to industry, perseverance, and activity, from their love of ornament. It is, therefore, employed largely in jewelry and ornamental work. Silver has the same effect from our estimation of utility, because it may be employed for almost every article of family use. But neither gold nor silver can be converted into tools to facilitate human operations, but iron gives man power over every material on which he operates.

The plough, so important in the cultivation of the earth, is a very imperfect implement without iron. And so of every implement of agriculture, and the mechanic arts. Without

it, the felling of a tree is a work of immense labor. To build a house or a ship, almost an impossibility. The beautiful and convenient furniture of our dwellings, numerous carriages, and our clothing, depend on iron for their fabrication. One of the greatest causes of the rapid improvements of the present time, so vastly beyond any previous period, is the great improvement in working iron, and its adaptation to so many instruments of human comfort. Stoves, so uncommon a half century ago, are now in every kitchen, bed-room, and parlor, so purified as to bear heat without cracking by expansion; and, so far from being unhealthy, are allowed to be as conducive to health as to comfort. Thus what at this period appeared ruin and destruction, unsightly and repulsive, was, in reality, a preparation for the most important benefits to man. Broken and torn down trees and ferruginous mud were to become precious stores of good to a future world.

This important mineral is very generally diffused through and deposited in the earth. Water passing over beds of iron ore or masses. of decayed vegetables, into which iron enters largely, being the important coloring matter, combining with the iron, conveys it over flat

countries and into lakes, where it leaves a deposit of bog iron ore, which is found in alluvial districts. In Scandinavia, where the primitive strata are richly impregnated with iron ore, iron ore is found in the bottom of lakes so rich as

to yield sixty per cent. The iron is dredged out at different periods of ten, twenty, or thirty

years.

CHAPTER II.

THE whole history of the old world may be reduced to a scale of epochs and periods. Geologists have recognised several distinct periods in the earth's history, sufficiently clear and well authenticated, especially in the fossilbearing rocks, where the remains of once living organized beings are found. The following may be regarded as a scale giving some idea of our meaning; and which has the advantage of reducing the whole to an order which may be considered in distinct parts. A part of the outline may be found in the geological books.

The scale is divided into epochs and periods. The epochs are commonly divided into three; but in this scale we have divided it into five.

I. Epoch.

Primary Epoch.

1. The first period, The Gaseous state.