Here is a recipe that I have not yet tried.

It is from a very old cook book.
The Every-Day Cook-book and
Encyclopedia of Practical recipes.
Published in Chicago in 1892
It is in the Invalid Cookery section

A number of people in the newsgroup seem interested in Flax Seed.

FLAX SEED LEMONADE
Four tablespoons flax seed (whole)
One quart boiling water poured over the flax seed
Juice of two lemons, leaving out the peel
Sweeten to taste:
Stew three hours in a covered pitcher.
If too thick, put in cold water with the lemon-juice and sweetening.
Ice for drinking.
It is splendid for colds.

PJ