presents the laticiferous tissue altered by the roasting, and в the woody tissue. The pointed hairs are seen at C, and the sphæraphides at D, whilst E represents portions of fig seeds. The laticiferous and woody tissues, the presence of pointed hairs, and abundance of sphæraphides, form the chief distinctive microscopic characters of figs.

Date Stones.-These have been roasted, ground, and mixed with coffee, and the mixture sold under the name of "Melilotine

FIG. 22.-DATE STONE.

Magnified 150 diameters.

Coffee." The seed of the date is almost entirely composed of a hard horny substance, the thick-walled cells of which are filled with albuminous and fatty matter.

The microscopic structure of the date stone is very simple. consists chiefly of sclerogen cells, as shown in Fig. 22. These cells are very characteristic, and can be readily detected and identified in any sample of coffee to which a preparation of date stones has been added.

Dates. Recently these have been prepared and mixed with coffee, or with coffee and chicory, and sold to the public under the name of "Date Coffee."

The pericarp, or portion external to the stone, is composed of cellular and spiral tissues. The cellular tissue partly consists of small well-defined sclerogen cells, which are characteristic, and can be readily recognised. Date Coffee also contains the tissues of the stone shown in Fig. 22.

COCOA.

BOTANICAL ORIGIN.-The cocoa of commerce is prepared from the seeds of the plant Theobroma Cacao, which belongs to the natural order Byttneriacea. The term Theobroma implies "food for the gods," and the name was given to the plant by Linnæus, who is said to have had a great liking for the beverage prepared from cocoa. The Mexicans called it "cacaoa quahuitl," naming the preparation from its seeds "chocolatl," and there is no doubt we derive the words cacao and chocolate from these native names. The term cacao has been changed into the familiarly known word

cocoa.

The genus Theobroma contains a number of species, all of which are natives of the tropical parts of America, and the seeds of several of them are found in the cocoa of commerce. The most important, however, is Theobroma Cacao, which yields the best and finest seeds, and which is extensively grown in the West India Islands, Brazil, and Guiana; its cultivation has also been introduced into some parts of Asia and Africa.

The ordinary height of the tree ranges from 12 to 20 feet, but is sometimes much higher. The tree bears leaves, flowers, and fruit all the year round; but although mature and unripe fruit may be seen growing at one and the same time, the chief seasons for gathering the fruit are June and December. The plant, when

three years old, begins to bear fruit, but it does not reach its full productiveness till the seventh or eighth year. The leaves, which grow principally at the top of the tree, vary from 7 to 10 inches in length, and from 2 to 3 inches in breadth.

Description. The seeds of the cocoa tree are contained in a pod or fruit, which in shape is intermediate between that of a melon and a cucumber, and measures from 5 to 12 inches in length, and about 3 inches in diameter. The rind of the fruit is smooth, fleshy, and about half an inch in thickness, with a yellow and red tinge on the side next the sun. The seeds are arranged in five rows divided from each other by partitions, and embedded in a paplike pulp or spongy substance, which separates from the rind when the fruit is ripe, and has a sweet with a slightly acid taste. The number of seeds contained in the fruit is variable, and sometimes amounts (particularly in that grown in Central America), to upwards of forty. The fruit grown in the West Indies and some other parts is much smaller and contains fewer seeds.

The seeds are removed from the recently-gathered fruit, placed in heaps and covered with leaves, or put in boxes or pits in the ground for four or five days, until a certain degree of fermentation has taken place. They are then dried in the sun or before a fire, by which process they become dark in colour, and lose much of their peculiar, harsh and unpleasant taste.

In preparing the cocoa beans for dietetic use, they are roasted in the same way as coffee, in large revolving cylinders over charcoal fires. The main object in the roasting is to develop the greatest possible amount of aroma, and produce a cocoa of full flavour and character. In the process of roasting the loss of weight is estimated at 10 per cent.

After roasting, the beans are passed through a machine which gently cracks the kernels, reduces them to small fragments or nibs, and disengages the husks or shells, which thereby become easy of separation. This separation is effected by passing the crushed beans through a powerful winnowing machine, when the nibs

pass out at one end and the broken husks at the other. The nibs are afterwards subjected to a further process of winnowing in small hand-sieves, the object of which is to separate the short steely needle-like germs, and at the same time to remove by the hand all mouldy or discoloured fragments. The sifting in this case is done in small quantities at a time, in order that the whole of the nibs may be exposed to view, and that no objectionable portion may escape detection.

Nibs are the purest form in which cocoa is supplied to the public, but they require long boiling to effect their disintegration and to prepare an extract for use as a beverage. The beans or nibs, when reduced to a powder or paste, can be much more easily cooked, and it is in the ground state in which the great bulk of the cocoa, either mixed or unmixed with other substances, is prepared and sold to the public.

Of manufactured cocoas the two leading types are flake and rock cocoas. Flake cocoa is generally prepared from the entire roasted beans, which are ground in steel mills somewhat similar to those used for grinding coffee, and afterwards reduced to the condition of a coarse paste. Rock cocoa is prepared from the nibs ground to a smooth paste in a heated stone mill, the paste, while in a soft condition, being thoroughly mixed with certain proportions of sugar and some starchy substance such as arrowroot. some instances sugar only is mixed with the cocoa paste to form rock cocoas.

In

Most of the other preparations of cocoa, whether sold as soluble cocoa or chocolate, consist of mixtures of cocoa nibs with various substances ground together into a smooth paste. In the manufacture of soluble cocoas, arrowroot, sago, or some other starch, and sugar, either dry or in the form of a syrup, are combined with the cocoa-nib paste. The admixture of starch with the cocoa paste tends to mask the presence of the fat, and to render the cocoa more readily miscible with boiling water. The so-called soluble cocoas, although composed generally of the same