(A larger Aloe monograph by Lloyd can be found at: http://www.swsbm.com/ManualsOther/Aloe-Lloyd.PDF)
The genus aloe comprises a large family of succulent-leaved plants native to tropical countries. Most of the species have showy flowers and many are cultivated in hot-houses. Aloe succotrina "grows in the Indies, and especially in the Island of Soccotera" (Lam.), but has long been cultivated in England. It is a shrub five or six feet high, with a stem marked with the scars of the fallen leaves. The stem is at first simple, but when the plant is old the stem is usually divided. At the top of each branch is borne a large cluster of thick, crowded, fleshy leaves. Each leaf is one and one-half to two feet long, rounded beneath, flattened on the upper side, the margins being each a row of white spines. The flowers are in a large terminal spike-like raceme, proceeding from the center of the leaf cluster. The flowers are orange-red, nodding, cylindrical, each borne on a short peduncle, slightly exserted. The pistil has a three-celled, many seeded ovary and a long simple style.
The earliest history of the aloe plant is somewhat obscured by the fact that the name aloe, for example as it occurs in the Bible, relates to a substance entirely different from the inspissated juice of the various species of the modern aloe plant. The aloe of the Bible is the wood of aquilaria agallocha (Roxburgh) or lignaloes, which was used among the ancient nations as an incense, and was held in high esteem on account of its scarcity. With modern cathartic aloes it has nothing in common except the bitterness.
The aloe plant is considered by modern writers to have grown wild in India from a very remote period. It was most likely introduced into that country by the Arabs, who probably were the distributors of knowledge concerning the medicinal virtues of aloes. This drug was employed by Galen (254a), and later described by the Greek and Roman writers of the first century, chief among whom are Dioscorides (194) and Pliny (514), whose descriptions of aloes and its uses, however, bear much resemblance to each other.
Socotrine aloes appears to have acquired its reputation at an early date. Clusius (153) in 1593 reports that Mesue, the Arabian pharmaceutical writer, "the father of pharmacopeias," (who died about A. D. 1028), knew of the Socotrine origin of aloes, mentioning Persia, Armenia, and Arabia likewise as sources of aloes of commerce. Ibn Baitar (1197-1248) (214) speaks of aloes from the island of Socotra as being superior to that of the Arabian district of Yemen.
The name aloe socotrina was undoubtedly derived from the island of Socotra off the entrance to the Red Sea. Yet, some authors maintain that this appellation was by some given to the inspissated juice of aloe (succus citrinus) on account of the lemon-yellow color of its powder. (Usage accepts that Aloe Succotrina is the plant described by Lamarck, and that Aloe Socotrina is the commercial extract derived from certain species of aloes. Exceptions in the spelling of the latter word have occurred in older pharmacopeias.) Not all of the earlier medico-pharmaceutical writers who afterwards considered the drug refer to Socotrine or any other special kind of aloes. Hieronymus Bock (1556) (82) merely alludes to the drug being brought from India and Arabia, a statement already found in Dioscorides. He relates an instance where the aloe plant is cultivated in Germany under the name sempervivum as an indoor ornamental plant.
Samuel Purchas (1625) (527), however, in his important collection of travels, gives prominence to Socotrine aloes, and places on record the commercial transactions of British merchants with the king of Socotra. One of his contributors (William Finch, merchant) gives the following interesting information which he gathered about A. D. 1607, concerning the occurrence and preparation of aloes in the Island of Socotra:
"I could learne of no merchandise the iland yeeldeth, but Aloes, Sanguis Draconis, and Dates and, as they say on the shore of Aba del Curia, Blacke Ambergreese. Of Aloes I suppose they could make yearly more then Christendome can spend, the herbe growing in great abundance, being no other than Semper vivum, in all things agreeing to that description of Dioscorides in seed, staike, etc. It is yet all of a red pricklie sort, and much chamfered (grooved) in the leaves, so full of a rosin-iuyce that it is ready to breake with it. The chiefe time to make it, is when the winds blowe northerly, that is, about September, and that after the fall of some raine, which being then gathered, they cut in small pieces, and cast into a pit made in the ground, well cleansed from filth and paved; there it lieth to ferment in the heat of the sunne, whereby it floweth forth. Thence they take and put it in skinnes, which they hang up in the wind to dry, where it becommeth hard. They sold us for 20 Rials a Quintall which is 103 pounds English, but we were after told that they sold to others for 12, which considering the abundance and easie making, may be credible." Elsewhere the statement is made that "the Aloe of Socotra exceedeth in goodnesse that which is gathered in Hadhramut of the land of Jaman, Arabia, or anywhere else." 1800 lbs. of Socotrine aloes were bought at one time and 2,722 lbs. at another.
The ancient trade of the island has never increased, and in 1833, we are informed, only two tons were exported, while at present the manufacture and export seem to have ceased altogether. No doubt this results from unfavorable local conditions as well as the intrusive competition of other countries. In the sixteenth century or perhaps before, the aloe plant was introduced into the West Indies and was especially dwelt on by Ligon (1763) (383) as having occurred in Barbadoes as early as 1647-1650, which is only about twenty years after the English came into possession of this island (365). It soon became an article of export, appearing in the London market in 1693 (239). In this connection, however, it is strange that J. B. Labat, a French monk and careful student of nature, having visited the island of Barbadoes in 1700, fails to mention Barbadoes aloes among the staples (365). He says on this point: "Formerly much tobacco was planted, and subsequently ginger and indigo; cotton is now grown up in some parts of the island, but sugar is at present the only article to which attention is devoted." That his omission could not be from ignorance is shown by his careful reference to aloes when twenty-eight years afterwards (1728) he refreshingly describes the resources and the people of Senegambia on the west coast of Africa (365), and strongly advocates the use of aloes that may be made from aloe plants grown in abundance in that district, in the place of aloes from the island of Socotra which, in his opinion, possessed an imaginary superiority only "because it comes from afar and costs much." The three commercial forms of the drug then known, Socotrine, hepatic, and caballine aloes. Labat ascribes to one and the same origin, the differences resulting only from the mode of preparation, caballine "or horse aloes, the lowest grade, being made from refuse material."
Yet, Barbadoes aloes is not herein referred to. Whether this neglect is due to interruption of cultivation or to some other cause difficult to determine may never be settled. It is established, however, that Barbadoes aloes was exported from the island both before and soon after these reports. Samuel Dale, in 1751, expressly states (179) that aloes is brought to England from the island of Barbadoes in large gourds and that the inspissated juice has the properties of aloe succotrina.
From Cape Colony, Africa, where it was made at that date by Peter Van Wett (239), aloes has been an article of export since 1773.
Curacao aloes was known in the Dutch market in 1847, and appeared in the English market for the first time as late as about 1876.
The History of the Vegetable Drugs of the U.S.P., 1911, was written by John Uri Lloyd.