366 WISCONSIN STATE AGRICULTURAL SOCIETY. 
has passed, and with the earth the atmosphere, in order that the 
former may be fitted for the abode of man, and the latter become 
vivified with that life giving power which is the essential and lead¬ 
ing idea of our topic. Designating these changes as Epochs , we 
have Epoch I.; an immense aggregation of mineral and metalic 
substances, intensely heated, undergoing incessant chemical re¬ 
action, forming a protosphere, comprising in its huge bulk all the 
various substances which have entered into the composition of the 
solids, liquids and gases of this planet. 
Epoch II. By condensation, the result of the radiation of heat 
into space, there exists a molten globe—a seething cauldron of 
mineral substances, all in a state of fluidity, smothered with an 
atmosphere of immense depth, in four concentric zones: first, in 
proximity to the molten globe, a thick belt of chlorides, especially 
the chloride of sodium or common salt. Outside of this a zone 
of carbonic acid gas, and this enveloped by an immense volume 
of nitrogen, and highest of all and surrounding all, an enormous 
quantity of the vapor of water. 
Epoch III. The radiation of heat into space continuing, there is- 
formed a thin crust of solid minerals around the mass of molten 
rocks and metals, consisting mainly of silicates of little density, 
combined with alumina and alkali. Upon this crust, now reduced 
to real heat, there has been precipitated from the lower stratum of 
atmosphere a mass of chlorides, mainly common salt, sufficient to 
cover the solid crust of the globe to a depth of ten feet—a literal 
storm of salt—snow enveloping the entire planet. At length, the 
temperature of the atmosphere having been reduced below that of 
boiling water, a condensation of the immense mass of steam in 
the upper regions ensue, and the second storm which visited this 
world was a long continued deluge of hot rain, which, dissolving 
the salt on the surface of the earth, formed an ocean enveloped 
of salt water for the entire globe. 
Epoch IV. Through the influence of continued heat radiations, 
continents and islands gradually emerge from the deep, covered 
in process of time with a vigorous vegetation. It was the era of 
vegetable organisms, whose affluent and abundant growth have 
never since been equaled. Let it be remembered that all the car¬ 
bon and all the nitrogen was combined in the vegetable and ani- 
