Take the leaves of tarragon just before it blossoms, put a pound of
them to three quarts of the best white-wine vinegar in a stone jar,
and let them infuse sixteen days. Then drain it and strain through
a flannel bag; add for every two gallons a quarter of an ounce of
isinglass dissolved in sherry wine, and let it be agitated briskly in a
large stone bottle two days. Leave it a month to get fine, then draw
it off into clean dry glass bottles, which cork well and seal.