X Proceedings. ^January 30th, igo6. 



The most recent and reliable estimate of the total amount 

 of sea-water which exists gives it at 340 millions of cubic miles. 

 A cubic mile of sea-water contains, at the rate of about 4'3 

 ounces per gallon, iio million tons of common salt, and, in 

 addition, 3"6 of potassium chloride, 12 of magnesium chloride, 

 8 of magnesium sulphate, and 5*5 of calcium sulphate — all in 

 millions of tons. 



Sterry Hunt's hypothesis* was, shortly, as follows : — When 

 the earth was in an intensely heated gaseous condition, all the 

 elements which compose it would be in the free state, and would 

 only unite gradually as ihe temperature fell. When the temper- 

 ature reached i2oo°C. the crust at any rate would have become 

 solid, and would inevitably consist mainly of silicates such as 

 we are familiar with as forming the principal constituents of 

 eruptive and igneous rocks. Practically all the chlorine which now 

 exists as chlorides would then be in the atmosphere in the form 

 of hydrochloric acid ; the carbon which exists now as coal, as 

 well as that in the carbonates of lime and magnesium which 

 now form such an important part of the earth's crust, would also 

 be in the atmosphere as carbonic acid gas, and in all probability 

 the sulphur which now exists in the various natural sulphates 

 and sulphides would be in the atmosphere as well, either in the 

 form of sulphur dioxide or trioxide. The whole of the water 

 would also be in the atmosphere in the form of vapour, 

 so that this primeval atmosphere must have exerted an 

 enormous pressure — possibly 300 or 400 times its present 

 pressure. As the temperature fell, the water vapour would 

 at last condense to liquid water. The condensation would 

 begin at 37o^C (the critical temperature of water), and the water 

 would immediately dissolve in it some, at any rate, of the acid 

 gases from the atmosphere. The primitive ocean would there- 

 fore be a highly heated dilute solution of hydrochloric and 

 sulphuric acids. The chemist will readily understand how 

 rapidly this would attack many of the natural silicates, the acids 

 finally becoming completely neutralised, and the ocean becoming 



*Che)incaI Neivs, vol. 15, p. 314. 



