The microscope shows that the outer layer of the pericarp just beneath the epidermis contains, with its collection of brown cells, an interior mass of fibro-vascular bundles traversing a mass of tissues of constructed parenchymous-walled cells, containing resin and tannin and small crystals of calcic oxalates. The seed contains much starch in minute grains, and yields from 3 per cent. to 4¼ per cent. of volatile oil, by distillation. This oil is composed mainly of eugenol C10H12, and very closely resembles the oil of cloves in all respects, but in odor, the difference being in the nature of the sesquialteral accompanying the eugenol. Its specific gravity is 1.04 to 1.05 at 15 degrees C. The yield of oil from the leaves is nearly 1 per cent.
Polarized light is a most important aid in examining powdered allspice, as it brings out strongly the stone cells and ligneous tissue ([Fig. 1], Chap. III), and differentiates these from the great mass of other matter. It also makes the oil cavities distinct.
It is hard to give a true chemical composition of pimento, but a good understanding of the tannin should be known, and especially a good estimation of the volatile oil. The amount of ash found in pimento is about 6 per cent. in the whole and 5 per cent. in the powdered state.
The chemical composition of a sample of whole pimento was found to be as follows:
| Water, | 6.19 |
| Ash, | 4.01 |
| Volatile Oil, | 3 to 4½ |
| Fixed Oil, | 6.15 |
| Crude Fiber, | 14.83 |
| Undetermined, | 59.28 |
| Albuminoids, | 4.38 |
| Nitrogen, | .70 |
| Tannin Equivalent, | 10.97 |
| Oxygen Required, | 2.81 |
The best adulterant is baked barley.
The specific gravity of the volatile oil is 1.04 to 1.05 at 15 degrees C.
Pimento meal loses its aromatic flavor very rapidly.
[[2]]The taste of allspice is warm, aromatic, pungent, and slightly astringent, and it imparts its flavor to water and all its virtue to alcohol. The infusion with water is of a brown color, and reddens litmus paper. Allspice yields volatile oil by distillation, a green fixed oil, a fatty substance in yellowish flakes, and tannin, gum, resin, sugar, coloring matter, malic and galic acids, saline matter, moisture and lignin.