544 Transactions of the Canadian Institute. [Vol. VII. 



thin crust and easily affecting the depression. These phenomena 

 would be repeated at other points as the temperature of the crust and 

 the atmosphere gradually lowered, until at a point below ioo°C. nearly 

 all of the water originally present in the atmosphere had condensed to 

 form the oceans of the globe. 



The composition of the ocean would follow from the occurrence of , 

 the soluble chlorides, sulphates and carbonates of the metals which 

 came in contact with the first condensations. As pointed out, the con- 

 densation of superheated water would convert the chlorides of mag- 

 nesium, iron and aluminium into magnesia (Mg O) oxide of iron 

 (Fe2 O3) and alumina (AI2 O3), the first of which is soluble only in 

 55368 parts of hot or cold water,* while the two latter are practically 

 insoluble, even in dilute acids. The magnesia, of course, would dissolve 

 in water which contained either hydrochloric or carbonic acids, but the 

 amount dissolved would, on account of the slight quantity of these 

 acids in the water, be very small. The other chlorides, namely, those of 

 sodium, potassium and calcium, although equally abundant, would not 

 be leached out of the rock surface in equal amounts. The solubilities of 

 these salts differ. For example, 100 parts of water dissolve at 99^0 154 

 parts of calcium chloride, 56.3 parts of potassium chloride, but only39.7 

 parts of sodium chloride. In consequence there would be different 

 quantities of each chloride dissolved, and the calcium chloride would by 

 far predominate, while the potassium chloride would be more abundant 

 than the corresponding sodium compound. There would, as already 

 pointed out, be very little ferric chloride and what would be dissolved 

 would gradually all be converted, first into the colloidal ferric hydrate, 

 and eventually into the insoluble oxide of iron. 



It does not follow that the ocean would contain, even after a long 

 period of action on the rockcrust, the whole of the chlorides of 

 calcium, potassium and sodium originally disposed over and diffused 

 through the now more or less rigid rockcrust. The constant washing 

 out of the land areas would no doubt tend to remove these salts from 

 the rocks until there would be little left in the latter and at the same 

 time they would become correspondingly more abundant in the sea 

 water. But other salts would begin to appear there also. The magnesia 

 derived from the chloride of magnesium, through the action of super- 

 heated water, would, under the action of carbonic acid in the rain water, 

 go into solution as carbonate, but the amount so dissolved, would, on 

 account of its low degree of solubility, be very small and it would only 



*Fresenius, Liebig's Annalen, Vol. 59, p. I2.-5. 



