The Arabian physicians, it is probable, all speak of indigo; but it is unfortunate that in this point we must depend upon very incorrect Latin translations. It appears also that they often repeat the information of the Greeks, in regard to articles of the Materia medica, without having been acquainted with them themselves. Rhases, who lived at the end of the tenth century[639], mentions, “Nil, alias Indicum.” Avicenna, who died in 1036, often speaks of indigo[640]; but in the margin of the wretched translation it is remarked, that under the term _Indicum_, alum (or much rather green vitriol) is to be understood. In a passage, however, where he speaks of dyeing the hair black, he certainly alludes to indigo, which, according to the translation, produced _colorem pavonaceum_, or a violet colour. In the Latin we find “Indicum indum bonum,” and this awkward expression Salmasius explains by remarking, that the words in the Arabic are _Alusma Alhendia_, that is, Indian woad. In the same place he mentions _Indicum carmenum_, a kind of indigo which did not dye so much a violet colour as a black, that is to say with the addition of green vitriol. Carmania, indeed, bordered on Gedrosia, which is the proper country of indigo, where the best is still prepared at Guzerat. In the explanation of some Arabic words, printed in my copy of Avicenna, _Indicum_ is translated _granum Nil_. Serapion, about the end of the eleventh century, mixed together, as appears, every thing that the Greeks have said in regard to indigo and woad. Averroes, in the middle of the twelfth century, mentions the medicinal qualities of indigo as given by the Greeks, and adds, that it was much used for dyeing.