------------------------------------------------------------------------ [Illustration: SKELETON OF GENUINE TEA-LEAF.] But in order to better detect the presence of spurious leaves in tea a keener knowledge of the botanical formation of the true tea-leaf is requisite, for which purpose the use of a microscope will be found an invaluable aid. Tea-leaves in general construction bear a strong resemblance to those of the willow and many other plants of the kind, vary widely in size and form, being much smaller, more deeply serrated, and ending more regularly just short of the stalk. The venations are very characteristic, the veins running out from the middle rib, almost parallel with each other, altering their course before reaching the extremities, and turning so as to leave a bare space within the border. When infused and unfolded it is of a bright-green color, the loopings together of the principal veinings in the true leaf being very characteristic. While the spurious leaf is either of a greenish-yellow or reddish-brown color, and irregular in form under the same conditions or when deprived of its cosmetics. To still better distinguish between them treat a sample of the suspected tea as in making an ordinary infusion to soften and expand the leaves, then separate and uncurl them and lay flat on a piece of glass or other smooth surface for comparison with the genuine leaf. Next see that they agree in description and formation, but more especially in the venations and serrations. Or soak the leaves in hot water, and carefully unroll and closely examine their formation and structure and then compare closely. The epidermis of the lower surface of the true leaf can be with a little caution detached in small portions with a sharp razor, and then analyze the frame or skeleton of the leaf in a little water or glycerine, under a microscope, comparing the venations and serrations with those of the genuine tea-leaf. Still another simple and inexpensive test is to boil a few of the suspected leaves for a minute or two on a watch glass, with a little distilled water, and add an equal portion of burnt magnesia, treating the whole until it is reduced to a large-sized drop. If no crystalline sublimate is obtained therefrom by the operation the leaves cannot be those of genuine tea.