COMMENTARY. In the second Section we have stated so fully the nature of the leuce, and the difference between it and its cognate affections, that it will be unnecessary for us now to resume the subject. It is there mentioned that leuce is Celsus’ third species of vitiligo, and the _baras_ of all the Arabian translators, with the exception of Stephanus Antiochensis, the translator of Haly Abbas, who applies the term _lepra_ to it. It was therefore the white species of leprosy. All the medical authorities represent it as an intractable disease, not only the cuticle being altered in structure, but also the flesh below, and even the hairs, having undergone a change of colour. All direct us to prick the skin with a needle, and, if it bleed, the cure is to be attempted; but if a slight colourless fluid issue from it, the case is to be abandoned as hopeless. They consider it as arising from debility of the assimilative faculty of the part which can no longer convert the nutritive juices into their proper consistence. All recommend nearly the same treatment. The diet is to be regulated with a strict abstinence from gross food; if there be plethora, venesection is to be premised; then drastic purgatives and emetics are to be given, and the parts affected are to be rubbed with stimulant and caustic applications, containing hellebore, nitre, sulphur, misy, red arsenic, &c., or even the actual cautery may be applied. In short, all treat the disease in nearly the same manner as our author. (See in particular Serapion and Avicenna.) Aristotle, we believe, is the first Greek writer who makes mention of leuce. He calls it a disease in which all the hairs of the body turn white. (Hist. Nat. iii, 11.) “The snow-white leprosy” of the ancient Jews was the leuce of the Greeks. Moses describes very correctly the method of distinguishing it from the alphos and melas; (Leviticus, c. xiii.) The symptoms of leuce are given in the 3d verse; of the alphos in the 4th; of the melas in the 6th. He calls it contagious, which might lead us to suspect that elephantiasis was mixed up with the leprosy of the Jews. This opinion is further confirmed from what is mentioned by Josephus of its being said that his countrymen were driven out of Egypt because they were affected with leprosy. (See also Justin. xxxvi, 20, and Tacit. Hist. v, 3.) Now we know that elephantiasis was endemial in that country. (See chap. i.) The English translation of this chapter is very inaccurate, the translators having evidently failed to recognize the nice distinction between cognate diseases, laid down by the Jewish legislator. Leuce is still common in tropical climates. Negroes affected with it are called Albinos. It is merely an aggravated variety of the _Lepra vulgaris_. SECT. VI.—ON WHITE AND BLACK ALPHI.