structures; but in white pepper we may expect to find principally the large angular cells which form the central substance. It may be observed that in the black particles of ground pepper little evidence of structure is in general to be noticed; it is necessary, to obtain a view of their microscopical appearance, that they should first be discoloured with chlorine, and separated into pieces with needles.

Genuine white pepper, consisting exclusively of the central part of the seed, exhibits under the microscope a number of cavities filled with starch granules; these granules are so very small that they possess, generally, a state of molecular movement, and resemble spherules of oil rather than starch granules.

The active properties of black pepper depend upon an acrid resin, a volatile oil, and a crystallizable substance called piperine; the resin is situated chiefly in the outer part of the cortex, the volatile oil in the inner part, and the piperine in the cells of the seed itself.

Adulterations of pepper.-Pepper may be adulterated with linseed (see woodcut), mustard seed (p. 54), wheat

flour (p. 15), and ground rice (p. 15).

It is also

said to be adulterated with burnt crust of bread

(M'Culloch's 'Commercial Dictionary') and with oil cake. (Normandy.)

The sweepings of the floors of the spice-warehouses, or the siftings of the whole pepper berry, are known in the trade as pepper dust, or P. D., or H. P. D., hot pepper dust. This substance is used to mix with ground pepper, and thus alters its quality without, however, adulterating it. Pepper husks.-The cortex of the pepper berry is occasionally ground and made into black pepper. In this case the particles of pepper are much larger; the microscope will help to detect the fraud.

A spurious or factitious kind of pepper is alluded to by Accum, consisting of pressed linseed, common clay, and a portion of Cayenne pepper, formed into a mass and granulated, by being first pressed through a sieve, and then rolled in a cask.

CAYENNE PEPPER

Consists of the seeds of Capsicum annuum and Capsicum frutescens, ground and reduced to powder, the latter yielding the best description of cayenne pepper.

Capsicum annuum is a native of America, but is also cultivated in the West and East Indies, and to some extent in green-houses in England and other European countries. It is one of the most productive plants of the tropical climates. When immature the berries are green, they gradually become red on ripening; in this country the plant flowers in July, and ripens its pods in October. The berries are used both in the green and red states. In the recent state they are employed for pickling; when dried and reduced to powder they constitute cayenne pepper.

The dried berries are commonly sold under the name of chillies; in this condition they are more or less shrivelled, oblong, broad at the base, pointed at the extremity, the stalk being usually adherent to the broad end. They vary much in size and form; the largest are two or three inches long, and at the base are an inch or more wide; they are distinguished, according to their size and shape, into longpodded, short-podded, and heart-shaped. The pods of this capsicum are hot and pungent, but have no aroma.

The pods of the Capsicum frutescens constitute what is known as the Guinea or bird pepper, and, when ground, furnish the best description of cayenne pepper. They are small, scarcely an inch in length, a line or two broad, and of a deep orange-red colour. Each berry incloses usually about a dozen flattened reniform seeds. The pods are hotter and more fiery than those of the Capsicum annuum ; they are likewise to some extent aromatic.

Two other species of capsicum have been denominated, from the form of the fruit-1st, cherry chilly or cherry pepper, or Capsicum cerasiform; and 2d, bell pepper, or Capsicum grossum.

The following analysis of the capsicum berries gives an idea of their chemical composition :

Capsicin, the active principle of cayenne, is obtained by digesting its alcoholic extract in ether and evaporating the ethereal solution. It is a thick fluid, of a reddish-brown colour. Half a grain of it, volatilized in a large room, causes all who inspire the air of the room to cough and sneeze. By exposure to air and light it solidifies; it is slightly soluble in water and in vinegar, but very much so in alcohol, ether, oil of turpentine, and the caustic alkalies. Each capsicum berry is made up of three parts.

1. An outer skin or epidermis.

2. The parenchyma.

3. The seed.

The epidermis is composed of a single layer of flattened cells, and contains numerous oil globules of an orange colour. The parenchyma consists of smaller and rounder cells than the preceding, and their cavities exhibit also a very large quantity of oil. A vertical section of the outer

surface of the seed furnishes a number of tooth-like processes, having a somewhat radiate disposition and surmounted by a layer of tortuous cells; the seed proper consists of minute angular cells, the cavities of which are filled with globules of oil.

The accompanying woodcut shows the structure of the

smaller red particles of pounded cayenne pepper; a sample of this spice was placed on the microscope glass, the larger particles blown off, and the dust placed under the microscope previously moistened with water, and covered with a thin slip of glass.

Adulterations of cayenne pepper.-1. Red lead.-Test: agitate the powder in a phial with sulphuretted hydrogen water; the cayenne will assume a dark black colour. A solution of the adulterated cayenne, in dilute nitric acid gives, with iodide of potassium, a yellow precipitate of iodide of lead.

2. Common salt.-Test: treat the pepper with distilled water, filter, and test the fluid with nitrate of silver; an abundant precipitate is produced, insoluble in nitric acid.

3. Brick dust.-Test: burn the pepper, treat the ashes with water; add a drop of nitrate of cobalt to the insoluble residue, and heat it with the blowpipe on a charcoal support; the mixture will turn blue from the alumina, if brick dust be present.

4. Red ochre. Venetian red, or colours containing iron. -Test and quantitative determination: treat the ground pepper with dilute hydrochloric acid; filter, and add ammonia in excess to the acid solution, when a red-brown precipitate will appear if iron be present. Collect the precipitate upon a filter, wash with distilled water, dry and burn the filter in a weighed platina or porcelain crucible. The weight of the ashes shows the quantity of iron (in the form of anhydrous peroxide) contained in the pepper; 100 parts of the ashes correspond to 70·00 parts of iron.1

1 When very accurate results are required, substract the weight of the ashes of an empty filter (similar in size to that employed above) from the weight of the burnt filter and iron precipitate.