From Prof. Mott's Chart on the Composition, Digestibility, and Nutritive Value of Food.

Two of the most important points suggested by a study of tea are the few adulterations and the great difference between different varieties, comparing weight and bulk. Some kinds of very cheap tea are adulterated with sage and raspberry leaves, and leaves of other plants dried to simulate tea, and often flavored with essences to give an agreeable taste, but a vast amount of the tea which is sold is pure. Adulterations with chemicals are now rare, on account of the extensive cultivation of tea and the large quantities sold.

Teas vary greatly in weight,- that is, a given bulk of one tea weighs very differently from the same bulk of another. This is especially marked in the comparison of Oolong and Gunpowder.

Below are given the weights of a moderate-sized caddy-spoon of each of these teas.