Aloë ferox L., and hybrids obtained by crossing it with A. africana Mill. and A. spicata Thunberg, A. perfoliata Linn. (quoad Roxb.) and A. linguæformis are reputed to yield the best Cape Aloes.
A. africana Mill. and its varieties, and A. plicatilis Mill. afford an extract which Pappe[2543] says is thought to be less powerful.
A. arborescens Mill., A. Commelini Willd. and A. purpurascens Haworth are stated to produce a portion of the Cape Aloes of commerce.[2544]
Various species of Agave, especially A. americana L., are largely grown, since the first half of the 16th century, in the south of Europe, and popularly called Aloë. All of them are plants of Mexico, while the true aloes are natives of the old world. Botanically the genus Agave differs from Aloë, in that the former has the ovary inferior, while in the latter it is superior. From a chemical point of view there is also no analogy at all between Aloë and Agave.
History—Aloes was known to the Greeks as a production of the island of Socotra as early as the 4th century b.c., if we might credit a remarkable legend thus given in the writings of the Arabian geographer Edrisi.[2545] When Alexander had conquered the king of the Persians and his fleets had vanquished the islands of India, and he had killed Pour, king of the Indies, his master Aristotle recommended him to seek the island that produces Aloes. So when he had finished his conquests in India, he returned by way of the Indian Sea into that of Oman, conquered the isles therein, and arrived at last at Socotra, of which he admired the fertility and the climate. And from the advice which Aristotle gave him he determined to remove the original inhabitants and to put Greeks in their place, enjoining the latter to preserve carefully the plant yielding aloes, on account of its utility, and because that without it certain sovereign remedies could not be compounded. He thought also that the trade in and use of this noble drug would be a great advantage for all people. So he took away the original people of the island of Socotra, and established in their stead a colony of Ionians, who remained under his protection and that of his successors, and acquired great riches, until the period when the religion of the Messiah appeared, which religion they embraced. They then became Christians, and so their descendants have remained up to the present time (circa a.d. 1154).
This curious account, which Yule[2546] says is doubtless a fable, but invented to account for facts, is alluded to by the Mahomedan travellers of the 9th century[2547] and in the 10th by Masudi,[2548] who says that in his time aloes was produced only in the island of Socotra, where its manufacture had been improved by Greeks sent thither by Alexander the Great.
Aloes is not mentioned by Theophrastus, but appears to have been well known to Celsus, Dioscorides, Pliny and the author of the Periplus of the Erythrean Sea, as well as to the later Greek[2549] and the Arabian physicians. From the notices of it in the Anglo-Saxon leech-books and a reference to it as one of the drugs recommended to Alfred the Great by the Patriarch of Jerusalem, we may infer that its use was not unknown in Britain as early as the 10th century.[2550]
At this period and for long afterwards the drug was imported into Europe by way of the Red Sea and Alexandria. After the discovery of a route to India by the Cape of Good Hope the old line of commerce probably began to change.
Pires, an apothecary at Cochin, in a letter on Eastern drugs[2551] addressed to Manuel, king of Portugal, in 1516, reports that aloes grows in the island of Çacotora, Aden, Cambaya, Valencia of Arragon, and in other parts,—the most esteemed being that of Çacotora, and next is that of Spain; while the drug of Aden and Cambaya is so bad as to be worthless.
In the early part of the 17th century there was a direct trade in aloes between England and Socotra; and in the records of the East India Company there are many notices of the drug being bought of the “King of Socotra.” Frequently the king’s whole stock of aloes is mentioned as having been purchased.[2552]