An alchemist once accidentally followed a river backwards, starting at the source, not knowing at the outset that the tiny spring would become a stream, the stream a creek, the creek a river, the river an estuary, and the estuary an endless ocean. Being an alchemist, he took samples of the water at every stage, storing them in little glass bottles. On the seashore he tested them all. And aside from insufficient variations in impurities, salinity or mineral compositions, he noted the obvious but inscrutable fact that all the glass bottles contained the same element of water, regardless of the stage of the journey during which they were filled. The alchemist watched the shore birds and tried to remember all of the fading landscapes.