"Whilst I resided in Philadelphia, in 1782, and 1783, I discovered that
the shad brought to market from the Scuylkill were very superiour in
flavour and firmness to those taken in the Delaware, which must proceed
from their food in that river, previous to their going to the sea; as they
are taken by the nets of the fishermen, before they are six hours in that
river, on their return. I cannot think it a romantic idea, that the waters
are impregnated with certain particles, on which they have been accustomed
to feed; which is sufficient to allure them to where they were originally
spawned; or that they are piloted there by some of the old fry. This idea
will not appear improbable, when we consider the general laws which seem
to control the whole finny tribe; and what would be the consequence should
they be thrown down? The cod-fish which occupy the banks of Newfoundland,
between the latitudes of 41 and 45, are very different, and are kept so
distinct, and are so similar on the respective banks, that a man
acquainted with that fishery will separate those caught on one bank from
those of another, with as much ease as we separate the apple from the
pear.
"I am, &c.
"Lincoln."
_Baltimore, 14th October, 1794._