I found this in an old cookbook.  It was from an old Army publication printed during the Apache Wars in the 1880’s.

Cut a piece of crusty bread, about a 1/4 pound in weight, place it upon a toasting-fork, and hold it about six inches from fire; turn it often, and keep moving it gently until of a light-yellow color, then place it nearer the fire, and when of a good brown chocolate color, put it in a jug and pour over 3 pints of boiling water; cover the jug until cold, then train it into a clean jug, and it is ready to use.

Never leave the toast in it, for in summer it would cause fermentation in a short time.  A piece of apple, slowly toasted till it gets quite black and added to the above, makes a very nice and refreshing drink for invalids.