MRS. B. That, my dear, is rather the department of the botanist; we shall consider these different parts of plants only, as the organs by which the various secretions or separations are performed; but we must first examine the nature of these secretions. The _sap_ is the principal material of vegetables, since it contains the ingredients that nourish every part of the plant. The basis of this juice, which the roots suck up from the soil, is water; this holds in solution the various other ingredients required by the several parts of the plant, which are gradually secreted from the sap by the different organs appropriated to that purpose, as it passes them in circulating through the plant. _Mucus_, or _mucilage_, is a vegetable substance, which, like all the others, is secreted from the sap; when in excess, it exudes from trees in the form of gum. CAROLINE. Is that the gum so frequently used instead of paste or glue? MRS. B. It is; almost all fruit-trees yield some sort of gum, but that most commonly used in the arts is obtained from a species of acacia-tree in Arabia, and is called _gum arabic_; it forms the chief nourishment of the natives of those parts, who obtain it in great quantities from incisions which they make in the trees. CAROLINE. I did not know that gum was eatable. MRS. B. There is an account of a whole ship’s company being saved from starving by feeding on the cargo, which was gum senegal. I should not, however, imagine, that it would be either a pleasant or a particularly eligible diet to those who have not, from their birth, been accustomed to it. It is, however, frequently taken medicinally, and considered as very nourishing. Several kinds of vegetable acids may be obtained, by particular processes, from gum or mucilage, the principal of which is called the _mucous acid_. _Sugar_ is not found in its simple state in plants, but is always mixed with gum, sap, or other ingredients; this saccharine matter is to be met with in every vegetable, but abounds most in roots, fruits, and particularly in the sugar-cane. EMILY. If all vegetables contain sugar, why is it extracted exclusively from the sugar-cane? MRS. B. Because it is both most abundant in that plant, and most easily obtained from it. Besides, the sugars produced by other vegetables differ a little in their nature. During the late troubles in the West-Indies, when Europe was but imperfectly supplied with sugar, several attempts were made to extract it from other vegetables, and very good sugar was obtained from parsnips and from carrots; but the process was too expensive to carry this enterprize to any extent. CAROLINE. I should think that sugar might be more easily obtained from sweet fruits, such as figs, dates, &c. MRS. B. Probably; but it would be still more expensive, from the high price of those fruits. EMILY. Pray, in what manner is sugar obtained from the sugar-cane? MRS. B.