76 KANSAS CITY REVIEW OF SCIENCE. 



that of the solar photosphere. Being more dense than the surrounding gases 

 they would sink toward 'the center. This would bring them again into a great 

 heat which would revolatize them. While this was repeating itself at the surface, 

 the great pressure at the center would tend to liquefy the gases, and afterward 

 to solidify all those liquids which continually contract on cooling. This is an im- 

 portant point, first pointed out by Hopkins who, from mathematical calculations, 

 proved that while the mass was yet gaseous or liquid, the pressure must have 

 been sufficiently great to solidify the center. 



We have similar examples almost every day, when the different gases are 

 liquefied or solidified by artificial pressure. So long as this mass remained in the 

 gaseous or liquid state, the heaviest portions would sink deepest from the surface. 

 We may therefore safely conclude that the center of the earth is composed of the 

 heavy metallic oxides, possibly with some of the most refractory metals in the 

 native state. In the course of time the temperature would be sufficiently reduced 

 for the oxides of carbon, sulphur, and hydrogen to exist. These with the haloid 

 elements, nitrogen and perhaps an excess of free oxygen, would remain in the 

 outer portion of the gaseous envelope. 



Portions of the water formed would be decomposed by the chlorine, form- 

 ing chlorhydric acid. Other portions would subsequently unite with sulphuric 

 oxide to form sulphuric acid. When the temperature was sufficiently reduced, a 

 crust would be formed on the outside of the liquid mass, so that solidification 

 would be going on from the inside out and the outside in, with a great mass of 

 liquid matter between. These being the conditions it is easily understood how the 

 solid crust and all beneath it would be perfectly anhydrous, the basic oxides be- 

 ing united with silicic oxide to form innumerable silicates. 



It has been argued that the nebular theory could not be true, because, if the 

 elements had ever been free to move among themselves, they would have united 

 with reference to their greatest affinities, so that a sort of chemical stabiUty would 

 have been formed. Such arguments only betray a lack of chemical knowledge. 

 The oxides of the bases together with the oxides of silicon, and perhaps of boron 

 also, would have been formed, as I have tried to explain, under such conditions 

 as to entirely separate them from water and the volatile acids ; so that the forma- 

 tion of hydrated salts, of chlorides, bromides, iodides, fluorides, nitrates and sul- 

 phates, would have been impossible. In predicting chemical changes one should 

 carefully consider the environment. Temperature and pressure have a wonder- 

 ful influence. This outer crust of the earth, resting on the liquid beneath, 

 would be affected by contraction resulting from continual cooling, so that it 

 would present a very irregular surface. As soon as the temperature would per- 

 mit, the watery vapor, charged with the acids until then existing in the air, woujtd 

 be precipitated in enormous floods. 



At the present time, \yhen all the rain water must previously be vaporized by 

 the heat of the sun, according to Loomis, a flood of fifteen inches has fallen in six 

 hours. At that time, when all the waters of the ocean were held in vapor, the 



