that it is of a much cleaner and more even texture than the cassia bark, which is thicker and heavier by reason of the outer cork layer usually left on it. The cheaper and more common cassia is the bark of the Cinnamomum cassia, which comes from China, Indo-China, and India. It is of a darker color than that of cinnamon, of coarser texture, and as a rule about four times as thick. Most varieties of cassia bark are less tightly rolled than cinnamon, and are not arranged one within the other in layers. The outer surface is marked by elliptical spots left by the leaves, and by small, dark-brown, wart-like protuberances. Cassia does not have the wavy, light-colored lines found in the cinnamon. cinnamon and cassia barks are very aromatic in taste, somewhat astringent, and slightly sweet.

Both

Cassia buds are the dry flower buds of China cassia, and are found in the market both in whole and in powdered form. Powdered cassia often consists of a mixture of several varieties of bark, while the cheaper grades sometimes contain an admixture of the ground buds.

The best grade of cassia is that from Saigon, a much cheaper, from Batavia, while the cheapest is the China cassia.

The odor of cassia and cinnamon bark is due to the volatile oil, of which from 1 to 2 per cent is usually found. Cassia and cinnamon oil greatly resemble each other, the principal constituent in either case being cinnamic aldehyde, C,H,CH: CH.CHO. Besides this, one or more esters of acetic acid are present. Both oils are very pungent and intensely sweet. Starch is present in cassia to the extent of from 16 to 30 per cent. A very small amount of tannin is found, as well as cinnamic acid and mucilaginous matters. Cassia buds are somewhat similar in composition to the bark. They have, however, less starch and crude fiber, and higher contents of volatile oil and nitrogen than the bark. Richardson* has made analyses of a few samples of pure whole cinnamon and cassia, from which the following are taken:

Winton, Ogden, and Mitchell's * results of analyses of whole samples of cinnamon, cassia, and cassia buds are thus summarized:

Structure of Powdered Cassia under the Microscope. - Fig. 84, from Moeller, shows various elements of cassia bark as veiwed microscopically. (1) shows in cross-section a portion of the cork and outer layer of the bark rind, with flat cells nearest the surface, having somewhat thick walls and reddish-brown contents, and, farther in, the cells s, with mucilaginous material.

The stone cells of the intermediate layer of bark are shown at (2). Here the tendency of the stone cells is to be thicker on one side than on the other, as is plainly shown. (3) represents the structure of the inner layer of the bark, showing bast fibers b cut across, and more of the socalled mucilaginous cells s of large size, which normally contain the ethereal or volatile oil. The starch granules (4) are contained in great abundance in the polygonal cells of the parenchyma of the intermediate

*Twenty-second Annual Report Conn. Exp. Sta., 1898, pp. 204, 205.

and inner bark layers. (6) represents a fragment of a bast fiber, which is often shown in cassia powder with connecting parenchyma. The stone-cells of the cork are shown in plan view at (7). Very small, needlelike crystals of oxalate of calcium are occasionally to be seen if looked for carefully. They occur in the parenchyma cells of the inner and intermediate layers of the bark.

The microscopical structure of Ceylon cinnamon much resembles that of cassia. Cassia starch grains measure from 0.0132 to 0.0222 mm.,

being considerably larger and more abundant that those of true cinnamon. As a rule the bast fibers of cassia are larger, but shorter, than those of cinnamon, and provided with thicker walls.

Figs. 203 and 204, Pl. XXI, show various phases of pure cassia bark as photographed from water-mounted specimens of the powder. Cassia starch somewhat resembles that of allspice, but it is not as a rule found in masses containing as many granules as does the allspice starch. Very commonly two or three of the starch granules are arranged together in

such a manner that at first sight they appear to form a single large granule, but on more careful examination are seen to be two- and three-lobed, consisting of several smaller grains. Stone cells, which are very abundant in the powdered cassia, do not happen to be included to any extent in the photographed fields. Cassia stone cells are generally more oblong than those of allspice, and are more often brown in color, while the allspice stone cells are generally colorless.

A distinctive feature of powdered cassia consists in the long-ambercolored wood fibers, some distributed in bundles, and others arranged singly. These are very clearly shown in Figs. 204 and 205.

Yellow patches of cellular tissue with starch grains interspersed among them are very abundant in the powder.

The U. S. Standards place limits as follows: Total ash not to exceed 5%; sand not to exceed 2%.

Adulteration of Cinnamon and Cassia.-The commonest adulterants are cereal products and foreign bark. Besides these, the writer has found, in samples sold in Massachusetts, leguminous starches, pea hulls, nutshells, turmeric, pepper, olive stones, ginger, mustard, and sawdust. Much of the China cassia when imported contains an inexcusably large amount of dirt. In one sample Winton, Ogden, and Mitchell found over 15% of sand.

Ground Bark of the Common Trees, especially that of the elm, resembles in physical appearance ground cassia, and is to be looked for as an adulterant. Fig. 265, Pl. XXXVII, shows the appearance of ground elm bark. The fibers of cassia bark have starch granules as a rule interposed among them, while the foreign bark, usually of a much coarser texture, shows no starch connected with its structure.

Fig. 206, Pl. XXII, shows a water-mounted specimen of adulterated cassia powder, chosen from samples purchased in the Massachusetts market. Nothing but the adulterant (a foreign bark) shows in the field. The tissue is loose and considerably coarser than that of cassia bark.

PEPPER.

Nature and Composition.-Pepper is the dried berry of the pepper plant (Piper nigrum), a climbing shrub belonging to the family Piperaceae, native to the East Indies, but cultivated in many tropical countries. The height of the pepper plant is from twelve to twenty feet. When the fruit begins to turn red, it is gathered and then dried, by which process it turns black and shrivels up, forming the black peppercorns of com merce. They are spherical single-seeded berries, about 5 mm. in diam

merce. They are spherical single-seeded berries, about 5 mm. in diameter, covered with a brownish-gray epicarp, and having on the under side the remains of a short stem. At the top of the berry is an indistinct trace of a style, and of a lobed stigma.

Varieties of black pepper are named from the localities in which they are grown or from which they are shipped, as Singapore, Lampong, Sumatra, Tellicherry. Malabar, Acheen, Penang, Alleppi, Trang, Mangalore, etc.

White pepper is obtained by decorticating the fully ripened black peppercorns, or removing the dark skin. This is accomplished by macerating them in water to loosen the skin, which is then removed readily by drying and rubbing between the hands. White whole pepper grains are grayish white, and a trifle larger than the black pepper berries. They are nearly spherical in shape, and have a number of light-colored lines that, like meridians, run from top to bottom. The common varieties are Siam, Singapore and Penang, the latter being coated with lime.

The pungent taste of pepper is due in great part to its essential oil, a hydrocarbon of the formula C10H16, present in amounts varying from 0.5 to 1.7 per cent. Pepper oil contains phellandrene and a terpene.

Other important constituents of pepper are piperidine, and the crystalline base piperin, C17H19 NO3, insoluble in water, but soluble in ether, and in alcohol. Starch is present in pepper to a large extent. Burcker gives the following average percentage composition of black

Richardson's* analyses of three samples of whole black and two samples of whole white pepper, all pure, are as follows:

* U. S. Dept. of Agric., Bur. of Chem., Bul. 13, part 2, p. 206.

Nitrogenous

Matter.

Volatile Oil.

Fat, Piper-
Resin.
in,

and

Starch and
Dextrin.

Other Non

nitrogenous Matters.