HAP. XXII.] ORGANIC AND INORGANIC EVOLUTIONS. 169 



In inorganic forms, in those represented to us in the hottest stars 

 .and the stars of gradually lower temperature, \ve have forms pro- 

 duced by a method by which complication is brought about what this 

 method may probably be, we shall consider later on. Now the more of 

 these complications the more the early forms must have disappeared, 

 unless we may take it that they may have been made occasionally 

 to reappear by the destruction of the later forms ; that is a point to 

 bear in mind. If the simpler forms must go on combining to provide 

 the more advanced forms, then if all the simpler forms are so used up, 

 the only chance of getting the simpler forms again is to destroy some- 

 thing which had been previously made ; and we can quite understand, 

 of course, that there were many conditions of this destruction possible 

 at the time when the crust of the earth was being formed. But how- 

 ever that may be, the gaseous elements, together with the non-gaseous 

 elements first formed, would be the chief chemical substances on the 

 surface and over it. Now the substances over the crust, of course, 

 would be the gases, hydrogen, oxygen, nitrogen, and dealing with the 

 stellar evidence we may suggest carbon combined with them ; that is 

 to say, hydrocarbons, carbonic acid, and so on. On the surface, whether 

 the surface be one of land or water, we should expect, in addition to the 

 low melting point metals lithium and sodium, those three metals which 

 we know existed in the hottest stars long before the rest, magnesium, 

 calcium, and silicium. Lithium probably and sodium certainly exist in 

 some of the relatively hot stars ; the evidence also suggests sulphur, 

 and this is rendered more probable because of the simplicity of its 

 spectrum-series. Now these are very remarkable associations, and 

 seem far away from ordinary chemical considerations. Is it a mere 

 coincidence that they are the important substances in sea water 1 



Constituents of Sea-water. 



Chloride of sodium 77'75 



magnesium 10'87 



Sulphate of 473 



lime ... ... ... 3-60 



potash :.. 2-46 



Bromide of magnesium 0*21 



Carbonate of lime ... O34 



The most easily thinkable organic evolution under these circum- 

 stances would be that of organisms built up of these chemical forms, 

 chiefly because they would represent the more mobile or the more 

 plastic materials ; we should not expect organic evolution to have 

 begun in iron, but rather in something the most mobile and the most 



