Note 18 — Chapter XV · COUNT RUMFORD’S SUBSTITUTE FOR TEA AND COFFEE.

Ordinary tea contains about 2 per cent. of this. It may easily be obtained by making a strong infusion and slowly evaporating it to dryness, then placing this dried extract on a watch-glass or evaporating-dish, covering it with an inverted wineglass, tumbler, or conical cap of paper. A white fume rises and condenses on the cool cover in the form of minute colourless crystals. The tea itself may be used in the same manner as the dried extract, but the quantity of crystals will be less.