most perfect sort, the savages choose a young, vigorous tree, whose bark is without moss, or any parasite plant; and, above the first large branches, give the tree a deep wound with an axe. The myrrh which flows the first year, through this wound, is myrrh of the first growth; and never in very great quantity. This operation is performed some time after the rains have ceased; that is, from April to June, and the myrrh is produced in July and August. The sap once accustomed to issue through this gash, continues to do so spontaneously, at the return of every season: but the tropical rains, which are very violent, and continue six months, wash so much dirt, and lodge so much water in the cut, that in the second year, the tree has begun to rot and turn foul in that part, and the myrrh is of a second quality, and sells in Cairo about a third cheaper than the first. The myrrh also produced from gashes near the roots, and in the trunks of old trees, is of the second growth and quality, and sometimes worse. This however is the good myrrh of the Italian shops every where but in Venice. It is of a blackish red, foul colour, solid and heavy, losing little of its weight by being long kept; and it is not easily distinguished from that of Arabia Felix. The third and worst kind is gathered from old wounds or gashes, formerly made in old trees; or myrrh that, passing unnoticed, bas hung upon the tree ungathered a whole year; black and earth-like in colour, and heavy, with little smell and bitterness. This appa. rently is the caucalis of the ancients. Pliny speaks of stacte, as if it was fresh or liquid myrrh; and Dioscorides, (cap. 67,) says something like this also. However it is not credible that the ancients, either Greeks or Latins, placed at such a distance, could ever see the myrrh in that state. The natives of its country say, that it hardens on the tree instantly, on being exposed to air; and I, who was several months within 4 days journey of the place where it grew, and had the savages quite at my devotion to go and come from thence, could never see the newest myrrh softer than the state in which I send it; though I think it dissolved more perfectly in water, thau when it had been kept. Dioscorides too mentions a kind of myrrh, which be says was green, and of the con sistence of paste. But as Serapion and the Arabs say, that stacte was a preparation of myrrh dissolved in water, it is probable, that this unknown green kind of Dioscorides was, like the stacte, a com position of myrrh and some other ingredient, not a species of Abys sinian myrrh, which he could never have seen, either soft or green. It may be remarked, that when we buy fresh or new myrrh, it has always a very strong, rancid, oily smell; and when thrown into water, globules of an oily matter swim upon the surface. This greasiness is not from the myrrh; it is owing to the savages using goat.skins anointed with butter, to make them supple, in which to put their myrrh at gathering; and in these skins it remains, and is brought to market: so that, far from its being a fault, as some ig norant druggists at Rome and Venice believe, it is a mark that the myrrh is fresh gathered, which is the best quality that myrrh of the first sort can have. Besides, far from injuring the myrrh, this oily covering must rather at first have been of service; as it certainly imprisons and confines the volatile parts of new myrrh, which escape in great quantities, to a very considerable diminution in the weight. The piece of myrrh which I send you is what a fine tree, less than fifteen inches diameter in the trunk at the bottom, wounded in two places, produced at one of the wounds in the year 1771. And it may be regarded as the only unexceptionable and authentic evidence in Europe, of what the Troglodyte myrrh was; unless it be those pieces still remaining in my collection, and a piece, somewhat smaller than yours, which I gave to the king of France's cabinet at Paris. This piece which I send you, had lost near six drachms Troy of its weight, between the 27th of August, 1771, and the 29th of June, 1773. It has lost a very few grains since. It was kept, as were all the other pieces, with great care in cotton, sepa. rately in a box, to prevent its losing weight by friction. Opocalpasum.-At the time when I was on the borders of the Tal Tal, or Troglodyte country, I sought to procure myself branches and bark of the myrrh tree, enough preserved to be able to draw it; but the length and ruggedness of the way, the heat of the weather, and the carelessness and want of resources of naked savages, always disappointed me. In those goat-skin bags into which I had often ordered them to put small branches, I always found the leaves mostly in powder; some few that were entire, seemed to resemble much the acacia vera, but were wider towards the extremity, and more pointed immediately at the end. In what order the leaves grew I never could determine. The bark was absolutely like that of the acacia vera; and among the leaves I often met with a small straight weak thorn, about two inches long. These were all the circumstances I could combine, relative to the myrrh tree, too vague and uncertain to risk a drawing on, when there still remained so many desiderata concerning it; and as the king was obstinate not to let me go thither, after what had happened to the surgeon, mate, and boat's crew of the Elgin Indiaman, I was obliged to abandon the drawing of the myrrh-tree to some more 'fortunate traveller. At the same time that I was taking these pains about the myrrh, I had desired the savages to bring me all the gums they could find, with the branches and bark of the trees that produced them. They brought me, at different times, some very fine pieces of incense, and at another time, a very small quantity of a bright colourless gum, sweeter on burning than incense; but no branches of either tree, though I found this latter afterwards, in another part of Abyssinia. But at all times they brought me quantities of gum, of an even and close grain, and of a dark brown colour, which was produced by a tree called sassa; and twice I received branches of this tree in tolerable order; and of these I 'made a drawing. Some weeks after, walking in a Mahometan village, I saw a large tree, with the whole upper part of the trunk and the large branches so covered with great bosses and knobs of gum, as to appear monstrous; and asking further about the tree, I found that it had been brought, many years before, from the myrrh country by merchants, and planted there for the sake of its gum, with which these Mahometans stiffened the blue Surat cloths, which they got damaged from Mocha, to trade in with the Galla and Abyssinians. Neither the tree which they called sassa, nor the name, nor the gum, could allow me to doubt a moment that it was the same as what had been brought to me from the myrrh country ; but I had the additional satisfaction to find the tree all covered over with beautiful crimson flowers, of a very extraordinary and strange construction. I began then a drawing anew, with all that satisfaction known only to those who have been conversant in such discoveries. I took pieces of the gum with me. It is very light. Galen complains that, in his time, the myrrh was often mixed with a drug which he calls opocalpasum, by a Greek name; but what this drug was, is totally unknown to us at this day. But as the only view of the savage, in mixing another gum with his myrrh, must have been to increase the quantity; and as the great plenty in which this gum is produced, and its colour, makes it very proper for this use; and, above all, as there is no reason to think there is another gum-bearing tree, of equal qualities, in the country where the myrrh grows, it seems to me next to a proof that this must have been the opocalpasum. I must however confess, that Galen says the opocalpasum was so far from an innocent drug, that it was a mortal poison, and Irad produced very fatal effects. But as those Troglodytes, though now more ignorant than formerly, are still well acquainted with the properties of their herbs and trees, it is not possible that the savage, desiring to increase his sales, would mix them with a poison that must needs diminish them. And we may therefore without scruple suppose, that Galen was mistaken in the quality ascribed to this drug; and that he might have imagined that people died of the opocalpasum, who perhaps really died of the physician. First, beeause we know of no gum or resin that is a mortal poison: 2dly, because, from the construction of its parts, gum is very ill adapted for having the activity which violent poison has; and considering the small quantities in which myrrh is taken, and the opocalpasum could have been but in an inconsiderable proportion to the myrrh, to have killed, it must have been a very active poison: 3dly, these accidents, from a known cause, must have brought myrrh into disuse, as certainly as the Spaniards mixing arsenic with the bark, would banish that drug when we saw people die of it. Now this never was the case: it maintained its character among the Greeks and the Arabs, and so down to our days; and a modern physician thinks it might make man immortal, if it could be rendered perfectly soluble in the human body. Galen then was mistaken as to the poisonous quality of the opo. calpasum. The Greek physicians knew little of the natural history of Arabia, still less that of Abyssinia; and we who have followed them know nothing of either. This gum, being put into water, swells and turns white, and loses all its glue it resembles gum adragaut much in quality, and may be eaten safely. This specimen came from the Troglodyte country in the year 1771: a piece of myrrh from Arabia Felix, and a piece of gum of the sassa from Abyssinia, were packed up in another separate box, to be sent you for comparison, but forgotten by my servant. The sassa, the tree which produces the opocalpasum, does not grow in Arabia. Arabian myrrh is easily known from Abys sinian by the following method: take a handful of the smallest pieces, found at the bottom of the basket where the myrrh was packed, and throw them into a plate, and just cover them with water a little warm: the myrrh will remain for some time without visible alteration, for it dissolves slowly; but the gum will swell to five times its original size, and appear so many white spots among the myrrh. The pieces sent are, No. 1, Virgin Troglodyte myrrh. No. 2, the worst sort of Troglodyte myrrh, called cancabs. No. 3, Opocalpasum, from the myrrh country *. [Bruce. Phil. Trans. 1775. SECTION XI. Dragon's Blood. Calamus Rotang.-WOODV. THE calamus is a genus containing nine separate species: three of which supply us with useful and elegant canes; C. sispionum, which affords the common walking-cane; C. verus, which yields the elastic or pliable cane; and C. rotang, which produces the rattan or rotang. This last is also the source of the resin, called dragon's blood. The tree may be considered as a scandent kind of palm: the lower part of the stem, to the extent of two or three fathoms, is strong, erect, hollow, jointed, and beset with numerous spines; afterwards it takes a horizontal direction, and overruns the neigh bouring frees to the distance of fifty or even one hundred feet: the leaves are several feet long, and composed of numerons pinnæ, which are nearly a foot long, narrow, sword-shaped, and at the edges serrated with spinous teeth the flowers are produced in spikes, which separate into long spreading branches: the calyx is divided into six persistent leafits, three exterior and three interior; the former are very short and pointed, the latter are oblong, concave, rigid, and unite closely, so as commonly to conceal the inner parts of the flower: it has no corolla: the filaments are six, capil * Some years after this paper was sent to the Royal Society, Mr. Bruce, in bis Travels to discover the Source of the Nile, vol. v. gives a few other hints, which render it still more probable that the myrrh tree is a species of mimosa, |