by no means as clearly as by the use of chloral hydrate. Large polygonal masses of starch appear grouped as photographed in Fig. 256, Pl. XXXIV, if not rubbed out too fine under the cover-glass. Starch, indeed, is the most conspicuous element of pepper, being distributed more or less evenly throughout the mass. The powder may, however, be so finely reduced by abrasion under the cover-glass as to break up these starch masses wholly or in part, so that the granules may appear in much smaller groups or even singly. Fig. 255 shows such a field under a higher magnification. The individual granules of pepper starch average 0.003 mm. in diameter.

Besides the starch, and next to it the most numerous, one finds in the water-mounted black-pepper specimen many of the dark-yellow, thickwalled stone cells, patches of the colored parenchyma, and epidermis of the shell. Other elements of the perisperm, besides the starch, are seen in fragments, such as bits of resin, small droplets of oil, pieces of stems, and occasionally the needle-shaped crystals of piperin. Some of the rounded, cup-shaped cells are also usually found.

White pepper contains, of course, the same elements, but without the deeply colored stone cells and other characteristics of the shell, which has been removed from it.

U. S. Standards for Pepper.-The following limits of constituents have been adopted: For white pepper, non-volatile ether extract should not be less than 7%; starch should not be less than 52%; total ash should not be more than 3.5%; ash insoluble in hydrochloric acid should not exceed 0.3%; crude fiber should not exceed 5%. For black pepper, non-volatile ether extract should not be less than 6.75%; starch should not be less than 30%; total ash should not exceed 7%; ash insoluble in hydrochloric acid should not exceed 1.5%.

Adulterants of Pepper.-Pepper shells obtained in preparing white pepper, are not infrequently ground and added to the cheaper grades of black pepper. When a sample of black pepper is shown by the microscope to contain more shells in proportion to the other elements than could be possible in a ground whole berry, added shells are indicated. The analyst should, for comparison, grind in a mortar single berries of various grades, and familiarize himself with the appearance of the ground powder under the microscope, when the maximum amount of shells possible under natural conditions are present, noting especially the apparent number of stone cells of the outer coating. The familiar title of P. D. (pepper dust) originally given to ground pepper shells, stems, and "sweep

ings" is now applied in the trade not only to almost any cheap and appropriate material for admixture with pepper, but also, in a broader sense, to ground powder suitable as an adulterant for any spice.

The presence of pepper shells is indicated by an excess of ash, sand, and crude fiber, and a deficiency of starch.

Hilger and Bauer, also Hanus and Bien, advocate the determination. of pentosans as a means of detecting pepper shells.

Ground Olive-stones constitute one of the most commonly found foreign materials used as an adulterant of pepper. The powder, sometimes called "poivrette," is very like white pepper in appearance, is wholly inert in taste, and thus forms an admirable adulterant. While best detected by their characteristic appearance under the microscope, their presence may be shown by various color tests, although these do not differentiate olive stones from nutshells and similar woody materials.

Pabst has adopted for this purpose a test first suggested by Wurster for the detection of wood pulp in paper. The reagent is prepared as follows: In a porcelain capsule 10 grams of commercial dimethyl anilin are mixed with 20 grams of pure concentrated hydrochloric acid, and at least 100 grams of cracked ice are added. Then, while stirring, a solution of 8 grams of nitrite of soda in 100 cc. of water are added little by little, and the mixture allowed to remain for half an hour, after which 30 or 40 cc. of hydrochloric acid are added, and 20 grams of tin-foil. The reduction is allowed to go on for half an hour, heating on the waterbath, if necessary. The tin is then precipitated by granulated zinc, the liquid is filtered, and the filtrate neutralized with carbonate of potassium or sodium to the point of forming a precipitate, the precipitate being dissolved by a few drops of acetic acid. Finally the volume is made up with water to 2 liters, adding, before doing so, 3 or 4 cc. of a concentrated solution of sodium bisulphite, to prevent oxidation. The reagent thus prepared will keep for several years in a brown, tightly stoppered bottle.

If a pinch of pepper, which contains ground olive stones, be heated gently with a little of the above reagent in a test-tube, the stone cells of the adulterant will be colored a bright red brown, and the colored particles will be seen to settle to the bottom of the tube, after shaking, more quickly than the rest of the powder. Or, if the whole is poured from the test-tube into a porcelain dish, the color is more marked. Pure pepper is not colored under this treatment with the reagent.

Jumeau uses for a color reagent 5 grams of iodine in 100 cc. of a mixture of equal parts of ether and alcohol. Enough of the finely ground pepper to be examined is placed in a porcelain capsule to cover the

bottom of the dish, and sufficient iodine reagent is added to wet the entire mass, carefully avoiding excess. The thick paste is first mixed till homogeneous, and then allowed to dry in the air, after which it is broken up by a pestle, and the powder examined, either under the microscope, or by the naked eye. With pure pepper, a more or less deep-brown color is produced uniformly through the powder, but if olive stones are present, particles of these are colored yellow. With the naked eye as small an admixture as 2% of olive stones can thus be detected.

A solution of anilin acetate colors olive stones yellowish browr, while pure pepper appears grayish, or white.

Under the microscope olive stones are readily apparent, since the stone cells differ in size, form, and mode of grouping from those of pepper. Fig. 263, Pl. XXXVI, is a photograph of a water-mounted specimen of olive stones. They are for the most part entirely devoid of color, being long and narrow. In shape and manner of grouping they much resemble cocoanut shells (p. 433), but are distinguished from the latter from their lack of color.

Fig. 261 shows under low magnification a sample of pepper, bought on the market in Massachusetts, highly adulterated with olive stones. A large mass of the stone cells of the adulterant appears in the center of the field. Many of the stone cells are shown arranged end to end, so that what at first sight appear to be single, very long cells are in reality made up of several shorter ones. In ground olive stones one frequently finds, besides the stone cells, bits of the outer tegument of the seed, showing large cells with sinuous, rather thick walls; also bits of parenchyma, crossed frequently by fibro-vascular duct bundles.

Buckwheat Products.-Both the hulls and the middlings have been added to black pepper, and the middlings to white pepper. The starch of buckwheat possesses the added advantage, from the point of view of the spice-grinder, that it somewhat resembles pepper starch in microscopical appearance, not only in the shape of the starch granules, but also in the manner of grouping into masses. Compare Figs. 128 and 129, Plates II and III, showing buckwheat starch, with Figs. 255 and 256, Pl. XXXIV, respectively, showing pepper starch made under similar conditions of magnification, etc. The starch granules and masses are coarser in the case of buckwheat than of pepper.

Fig. 260, Pl. XXXV, shows a photograph of a pepper sample adulterated with buckwheat, masses of both starches appearing in the same field.

Other Adulterants found in Massachusetts samples of pepper have been wheat and corn products, nutshells, cayenne, charcoal, turmeric, rice,

sand, and sawdust. Charred cocoanut shells were at one time extensively used (see pp. 433 and 434).

Long Pepper, according to English analysts, has been used to a considerable extent as an adulterant. This is the fruit of the Piper longum and P. officinarum, both oriental species. The fruit, as its name implies, is long and cylindrical, while of about the same diameter as the spherical true peppercorns. Long pepper contains, as a rule, less than half the amount of piperin that true pepper does, and rather more starch than black pepper. Its taste is much less pungent than that of true pepper.

From its method of growth, long pepper is found with considerable dirt and sand adhering to the outer surface of the dried grains. This is due to the fact that the fruit often trails on the ground, and in gathering it the natives are not particular about removing the adhering soil. The surface of the fruit grains being very rough and irregular, much of the dirt remains dried thereon. The presence of long pepper thus materially increases the ash.

Long pepper possesses a very disagreeable, but peculiar odor, developed more especially when slightly warmed. For this reason, if for no other, it is not an ideal adulterant, since pepper containing it would not be palatable with warm food. At the present time it costs more than black pepper, and is used chiefly in mixed whole spices for pickles. Brown gives the following analyses of samples of long pepper:

According to Brown and Heisch, the granules of long pepper starch under the microscope are larger than those of true pepper, and more angular. Stokes,* however, finds no such marked difference in the size of starch granules and his experience is shared by the writer. When the two specimens (long and true pepper) are viewed side by side in water mounts under the microscope, the average size of the long pepperstarch grains is a trifle larger than those of true pepper, though, unless compared directly, the difference is not readily apparent. Stokes suggests a method of distinguishing the two by poiarized light. With crossed

Analyst 13, p. 109.

Nicols, so that a dark field is given, and with the specimen mounted in glycerin, true pepper starch shows an evenly dark appearance, using a low power, while with long pepper a "ghostly white" image is shown. Long pepper, when present in true pepper powder, may generally be rendered apparent by the development of the characteristic odor on heating. Bits of fluffy fiber from the catkin of the long pepper will always be found in the ground powder, and will be apparent under the magnifying-glass.

Microscopic examination of the crude fiber discloses the highly characteristic, large, beaded cells of the endocarp, also elements of the spindle.

RED PEPPER.

Nature and Varieties.-According to the U. S. Standards red pepper is the red, dried, ripe fruit of any species of Capsicum, a genus of the nightshade family (Solanacea), indigenous to the American tropics, but now cultivated in nearly all warm and temperate countries, and is of two distinct kinds: cayenne pepper or cayenne, the dried ripe fruit of C. frutescens, C. baccatum, or some other small fruited species of Capsicum, and paprika, the dried ripe fruit of C. annuum, or some other large-fruited species of the genus, excluding seeds and stems.

Boyles states that in the trade, the larger podded varieties are usually called capsicums and the smaller, chillies, the term cayenne being applied only to the ground product made from either or both capsicum and chillies.

Chillies are characterized by their extreme pungency and the small size of the pods, which seldom exceed 2 cm. in length. The leading commercial varieties come from Africa and Japan, the latter being the more brilliant in color. Zanzibar chillies, formerly the leading African variety, have given place in the market to Mombassa.

Capsicums formerly denoted low grade peppers of a brown color with pods 2 to 3 cm. in length, or even longer, produced in Africa, especially in the vicinity of the river Niger, also in Japan, Korea, and India, but now is used in a broader sense as noted above.

Paprika is a variety of C. annuum grown in Hungary. The powder is of a deep red color and has a sweetish, mildly pungent flavor.

Tolman and Mitchell † state that of the five grades of ground Hungarian paprika, named by Csonka and Varadi,‡ only three enter the

* Jour. Ind. End. Chem., 9, 1917, p. 301.

† Ibid., 5, 1913, p. 747.

Der Szegeder Paprika und der Szegeder Paprikahandel, 1907.