ABSTRACT
Introduction The most obvious and far-reaching question of marine chemistry is the one that many children have posed to their puzzled elders ‘Why is the sea salty?5 Once the reply advanced from ‘Because it is . . .5 to ‘Because water evaporates and falls again on the land as rain, while the salt stays behind in the sea5 (the first point is to be found in the book of Ecclesiastes), progress in understanding came to a halt. Even after experimental oceanography became established as a science late in the nineteenth century, it took about one hundred years of research - during which time the question had been refined to ‘Why is the composition of sea water as it is?5 - to answer it in any detail.
