126 TRAXSACTIOyS OF TEE AllERlCAN INSTITUTE. 



seemed as though the cheniici\l affinity ^vhic]l ftronght thciu toijether 

 and tended to make theui a nnit in combination, wa^i completely 

 suspended at these higher temperatures, so that one might suppose 

 that on the sun, and still more in these nebulous bodies, all the 

 elements were in a state of chemical indifference, or in other words, 

 of dissociation. The spectroscope told us that, because wc recognized 

 the spectra of the simple elements, and of the compound bodies. The 

 process of condensation which was going on in the sun must be going 

 on in all the planets. Our earth was once a luminous mass of vapor, 

 passing through a stage in jvhich it was self-luminous like the sun, 

 until it fin all}' became cool to such a point that it liquified and 

 became at last solid. The next question is, did the earth become 

 solid first at the circumference or at the center ? This is important 

 from- more than one point of view, and has been investigated by 

 astronomers, physicists, and chemists, and it seems pretty clearly 

 proved that the earth, if not solid to the center, must have a crust 

 several hundred miles in thickness. And it is probable that if the 

 cooling commenced at the center, that at least the surface would be 

 covered with a thin layer of liquid matter, which, on coolirig, would 

 give an uneven surface to the primeval globe. So far as the chemistry 

 of our planet is concerned, we have to deal only with this outer layer, 

 all the various elements of which must have existed either in that crust 

 or in the atmosphere which then surrounded it. AVe form a good idea 

 of this primeval crust, if we suppose the elements, l^ocks, air and 

 ocean to be brought together at the intense heat which then existed. 

 Under such conditions the lime, magnesia, alkalies — would all unite 

 into combination with silica and alumina, while the atmosphere would 

 contain chlorine, sulphur, carbon and hydrogen, together with oxygen 

 and nitrogen. This would form on the one hand a slag-like siliceous 

 mass, and on the other hand an atmosphere charged with acid-vapors, 

 yielding all the chlorine, sulphur and carbon in the form of acids, and 

 the water in the form of steam mixed with nitrogen and oxygen. 

 The weight of the atmosphere would be immense, and under its 

 pressure water and the less volatile acids would be liquified at the 

 high temperature, and these acid waters v\'ould collect in the depres- 

 sions of the earth's crust, M'hcre they would immediately decom})ose 

 the silicates, separating the silica and forming sulphates and chlorates 

 of the alkalies — lime and magnesia. This solution would form first, 

 sea water, and the action would continue till these affinities were 

 Batisfied. Then connneuced a new chemical process, the action of 



