244 
PEOFESSOE FOECHHAMMEE ON THE COMPOSITION 
The ocean is in fact such a lake, into which all the rivers carry what they have dissolved 
from the land, and from which pure water evaporates ; and whatever we think about 
the constitution of the primitive ocean, this effect of the rivers, which has lasted for 
thousands of years, must have had an influence upon the sea. Why do we not observe 
a greater influence of the rivers 1 Why does not lime, the prevailing base of river-water, 
occur in a greater proportion in the water of the ocean 1 In all river-water the number 
of equivalents of sulphuric acid is much smaller than that of lime, and yet we find in 
sea-water about three equivalents sulphuric acid to one of lime. There must thus be in 
sea- water a constantly acting cause that deprives it again of the lime which the rivers 
furnish, and we find it in the shell fishes, the corals, the bryozoa, and all the other 
animals which deposit carbonate of lime. From the proportion between sulphuric acid 
and lime in river-water and in sea-water, it is evident that these animals are able not only 
to deprive the water of its carbonate of lime, of which sea-water contains very little, but 
that they also must decompose the sulphate of lime, a decomposition which probably 
depends upon the carbonate of ammonia which is formed by the vital process of these 
animals. I have shown that a salt of ammonia occurs in sea-water, certainly in small 
quantities, which however does not signify much, since the ammonia is constantly 
absorbed by the sea-weeds. Thus it is a chemical action of small animals which con- 
stantly deprives the sea of its excess of lime. 
Next to the lime we must consider the silica, which is a constant constituent of river- 
water, and the immense quantity of diatomacese, of infusoria, and sponges will account for 
the small quantity of it at any given time in sea-water. I shall name next the sulphuric 
acid. All the shells of shell fishes, all the carbonate of lime in the corals and bryozoa 
contain some sulphate of lime, about one per cent, or less, but all the sea-weeds attract 
a great quantity of sulphates, which by the putrefaction of the plants are changed into 
sulphurets ; and the sulphurets give again their sulphur to the iron, both that which is 
dissolved in sea-water, and that which in the form of oxide, combined with clay and 
other earths, is mechanically suspended in the water of the sea, principally near the 
shores. Thus the sulphur is made insoluble and disappears from the brine. The mag- 
nesia enters in a small quantity into the shells and corals, but only a small quantity is 
thus abstracted from sea-water, and at last the soda and muriatic acid or chlorine form, 
as far as we know, by the pure chemical or organico-chemical action that takes place 
in the sea, no insoluble compound. Thus the quantity of the different elements in sea- 
water is not proportional to the quantity of elements which river-water pours into 
the sea, but inversely proportional to the facility with which the elements in sea-water 
are made insoluble by general chemical or organo-chemical actions in the sea ; and we 
may well infer that the chemical composition of the water of the ocean in a great part 
is owing to the influence which general and organo-chemical decomposition has upon it, 
whatever may have been the composition of the primitive ocean. I shall, however, not 
dwell any longer on this side of the question, which deserves a much more detailed 
representation than I can give it here. 
