It does not appear to me, that the ancients had ever seen this plant, they describe it so variously; some will have it a tree, some a shrub, and some a plant only; and Prosper Alpinus, a modern, corroborates the errors of the ancients, by saying it is a kind of vine, (viticosus). The figure he has given of it is a very bad one, and leaves us entirely in doubt in what class to place it. The defect of the plant in Judea and in Egypt, and the contradiction in the description of the ancients as to its figure and resemblance, occasioned a doubt that the whole plants in these two countries, and Arabia also, had been lost in the desolation occasioned by the Mahometan conquest; and a warm dispute arose between the Venetians and Romans, whether the drug used by the former in the Theriac was really and truly the old genuine opobalsamum? The matter was referred to the pope, who directed proper inquiry to be made in Egypt, which turned out entirely in favour of the Venetians, and the opobalsamum continuing as formerly. A very learned and tedious treatise was published by Veslingius, in the year 1643, at Padua, where this affair was discussed at full length. As both parties of the disputants seem to argue concerning what it is from the misunderstood reports of what it was, I shall content myself briefly with stating what the qualities of the opobalsamum are, without taking pains to refute the opinions of those that have reported what the opobalsamum is not. The opobalsamum, or juice flowing from the balsam-tree, at first when it is received into the bottle or vase from the wound from whence it issues, is of a light, yellow colour, apparently turbid, in which there is a whitish cast, which I apprehend are the globules of air that pervade the whole of it in its first state of fermentation; it then appears very light upon shaking. As it settles and cools, it turns clear, and loses that milkiness which it first had when flowing from the tree into the bottle. It then has the colour of honey, and appears more fixed and heavy than at first. After being kept for years, it grows a much deeper yellow, and of the colour of gold. I have some of it, which, as I have already mentioned in my travels, I got from the Cadi of Medina in the year 1768; it is now still deeper in colour, full as much so as the yellowest honey. It is perfectly fluid, and has lost very little either of its taste, smell, or weight. The smell at first is violent and strongly pungent, giving a sensation to the brain like to that of volatile salts when rashly drawn up by an incautious person. This lasts in proportion to its freshness, for being neglected, and the bottle uncorked, it quickly loses this quality, as it probably will at last by age, whatever care is taken of it.