Herbs ought to be gathered, when the leaves have attained their full growth, though previously to the appearance of the flower-buds. With respect to the removal of leaves, no certain rule can be given; but flowers should be plucked on a clear day, when they are moderately expanded: after having been carefully selected, both herbs and flowers must be cautiously dried in a gentle heat, so that their strength and properties maybe more completely preserved: and, if they contain any subtle or volatile matter, it will be advisable to pulverize them as speedily as possible, and to keep such powder in close glass vessels.
All fruits, however, should be allowed to become perfectly ripe, before they are removed from their stems or branches, excepting sloes, and one or two other astringents, that lose their virtues, if suffered to remain on the trees till they attain to maturity. Nor should seeds be collected, until they begin to grow dry, and are about to drop or shed spontaneously; when they ought to be preserved in an open situation, without being separated from their husks; as these serve to protect them from injuries of the air and weather.
Under the article Preservation, we have alluded to a new and excellent method of keeping vegetables of every description in a sapid state, for many years, excepting cucumbers and radishes:—it simply consists in drying them on a plastered floor, or an oven, moderately heated by a fire made below the structure; so as to avoid singeing or burning the leaves, stalks, &c.; the whole process being conducted in the manner about to be described, and requiring no farther care in regulating the degrees of heat, than is necessary in the baking of thin biscuits; provided the former be exposed on their surface to the open air, for dissipating the moisture, while the latter are confined in an oven.
In order to succeed completely in this useful pursuit, the herbs and roots, as well as every species of fruit to be preserved, ought first to be cleaned, either by wiping, washing, and otherwise cleansing it in a manner similar to that practised for culinary purposes. The water should be completely drained, by placing the different articles on sieves, or frames on which canvas is expanded, or perforated boards, or similar contrivances. After repeatedly turning the leaves, stalks, or fruits, so that each side may become dry, they must be spread over a floor or oven, constructed on the principle before mentioned, till all their moisture be thoroughly evaporated; for, if the least humidity remain within the substance of such vegetables, they will become mouldy and corrupted. The best criterion for ascertaining the due degree of exsiccation, is that of the stalk breaking readily, and the leaves being easily reduced to powder between the fingers. In this shrivelled state, however, they could neither be packed nor conveniently transported: hence, it will be proper to remove them previously to a cellar, or other damp place, till they have become so pliable by the absorption of moisture, as to be compressed without crumbling to pieces. This degree of humidity is, according to experience, not detrimental to the preservation of the plants, and in its effects very different from that retained in their interior parts. Next, the vegeta-
