The collection of vegetables cannot be attended to by the apothecary, and, consequently, the directions necessary for that purpose are of less importance to him than a knowledge of the botanical characters of plants, and the appearances they assume when they are collected under proper circumstances and well dried: for inert plants are often introduced by the collectors among those which possess the most active properties; and from a careless or an improper mode of drying plants, the medicinal virtues of the majority of them are altogether destroyed. When, however, opportunities permit the apothecary to be his own collector, they should not be neglected; and the collection and drying of some plants, particularly of foxglove and hemlock, should never be left to the common collector. The following general directions are therefore given in the London Pharmacopoeia for collecting vegetable substances.

"Vegetables are to be gathered in dry weather, and when no dew nor rain is upon them: they are to be collected every year, and any which shall have been longer kept are to be thrown away." This is a direction of the utmost importance as far as regards the more active vegetable remedies, such as digitalis; for the skill of the most experienced physician will little avail the patient, if the drug which is ordered have lost its medicinal properties from being too long kept.

"Roots, for the most part, are to be dug up before their stems or leaves shoot forth." The object of this order is the obtaining the roots with their active principles in the most concentrated state, which may be effected by digging them up late in autumn, or early in winter, after the sap is completely detruded to the root, and the stem is withered, but yet attached to the root, by which its situation is pointed out. If any change in the composition of the juices takes place during the cessation of vegetation in winter, it is probable that the same will happen, if the root, after being dug up, be preserved in sand.

"Barks are to be collected at that season in which they are more easily separated from the wood." Spring is the season here alluded to; as at this time, after the sap begins to ascend, the bark is in general very easily separated. But a more important reason may be given for preferring this period, as in spring the active principles deposited in the proper cells of the bark are most abundant: thus, oak bark collected in spring contains four times more tannin than that which is collected in winter.1

"Leaves are to be gathered after the flowers have expanded, and before the seeds are mature." These should be in the most perfect state, free from disease, and full grown.

"Flowers are to be gathered when just opened." There is, however, one exception to this rule, namely, the red rose, which must be gathered before the buds are expanded.

"Seeds are to be collected when they are ripe, and before they drop from the plant. They ought to be preserved in their seed-vessels."