How the Waters of the Ocean became Salt. 169 
12. There are two ways by which we may account for the salinity 
of the ocean waters from very early periods of geological time. 
First, by supposing that the primeval waters were saturated with 
acid gases which were held in suspension in the vapour surrounding 
the incandescent globe; or secondly, that the salinity resulted from 
a process resembling that by which salt lakes of the present day 
have been formed.' 
138. We must, I think, concur with Dr. Hunt that from some 
cause or other, chlorine largely abounded in the waters of the 
primeval ocean, as by far the greater proportion of the salts are 
chlorides, and chlorine is but very slightly represented in river 
waters at the present day. 
14. In contrast to the above, which may be called “the chemical 
theory,’ we.may now consider that which may be called ‘the 
geological theory,” though it very much depends upon certain 
chemical processes. 
15. If we compare the analyses of waters brought down by rivers 
into the ocean at various parts of the globe we shall find that the 
matters in solution are very much the same as those which we 
find dissolved in oceanic waters; the proportions are doubtless 
immensely different, but the ingredients are essentially similar. 
Now, what are the dissolved ingredients of river waters? They 
are calcium, magnesium, sodium, potassium, a little iron, silica, 
alumina, and other matters, in combination with carbon-dioxide 
(carbonic acid gas), sulphuric acid, hydrochloric acid. Of these the 
carbonates of lime and magnesia are the most abundant, but chlor- 
ides of sodium and magnesium are almost always present even in 
waters where there can be no suspicion that they have been intro- 
duced by any artificial means. These constituents are also found in 
even larger proportions in the waters of natural springs; and in 
1 Of the former method Dr. Sterry Hunt may be considered the chief exponent, 
and in order that I may not unintentionally misrepresent his views I will give them 
here in nearly his own words. Referring to that period in the physical history of 
our globe in which it may be presumed to have been in a molten state surrounded by 
an atmosphere and an envelope of vapour of water, he says :—‘‘ There would be the 
conversion of all the carbonates, chlorides and sulphates into silicates, and the 
separation of the carbon, chlorine and sulphur in the form of acid gases which, 
with nitrogen, vapour of water, and a probable excess of oxygen could form the 
dense primeeval atmosphere. ‘The resulting fused mass would contain all the bases 
as silicates, and must have resembled (when consolidated?) certain furnace slags or 
volcanic glasses. The atmosphere charged with acid gases which surrounded this 
primitive rock must have been of great density. Under the pressure of a high 
barometric column condensation could take place at a temperature much above the 
present boiling point of water, and the depressed portions of the half-cooled crust 
would be flooded with a highly heated solution of hydrochloric and sulphuric acids, 
whose action in decomposing the silicates can easily be understood. The formation 
of the chlorides and sulphates of the various bases and the separation of silica would 
go on until the affinities of the acids were satisfied, and there would be a separation 
of silica taking the form of quartz, and the production of sea-water holding in 
solution, besides the chlorides and the sulphates of sodium, calcium, and magnesium, 
salts of aluminium and other metallic bases. The atmosphere being thus deprived of 
its volatile chlorine and sulphur compounds, would gradually approximate to that 
of our own time, but would differ in the greater amount of carbonic acid gas.” 
“« Chemical and Geological Essays,’’ p. 40 (1875). 
