When thus incommoded, the Egyptians of the lower class esteem water pernicious, and therefore rarely wash their eyes; but as the collected dust begins to cause an uneasy sensation, apply their fingers or a coarse cotton cloth to remove it. The higher orders, who are neat in their persons, and regular in their ablutions, are rarely observed to be greatly harassed by this complaint. And the progress of the disorder, when in its nascent state, has several times been stopped, under my observation, by the use of rose-water, solution of sacchar. saturn. &c. as in other places. But as no single one of these causes, nor even all of them together, appear sufficient to account for all the phenomena, another, more powerful, is to be sought; and none suggests itself more opportunely than that alleged by Savary, who imagines that the defect of vision is principally brought about by the habit of being exposed to the nocturnal air during the summer, at which season a heavy dew falls, and a great transition happens from the heats of the day. In fact, if the face of those who sleep exposed be not completely covered, an itching and unpleasant sensation is always felt in the eyes at rising. It is ordinarily experienced in the city, where, from being confined in the day, people feel most disposed to seek for coolness and refreshment on their terraces at night. The Mamlûks, and higher order of Arabs, that is, Mohammedan merchants, and the superior rank of Copts and Franks, are least affected, as being cleanly, not exposing themselves to the night air without necessity, and being well covered. The Arabs of the desert are as free from blindness as any people. They never sleep with the face exposed, and have moreover the advantage of being devoid of the dust and other supposed causes of psorophthalmia in the city. The disorder appears no where so much as in Kahira, because no where are all the causes so much combined: yet it is seen in Alexandria, Damiatt, and in Upper Egypt, which shews that the cause is not confined to Kahira. Among the poorer class of all countries prevails a kind of _insouciance_. That of Kahira is particularly exposed to the changes of temperature and the nocturnal dew, and is ill clothed. Hence the disorder is mostly found among the populace. A disposition to inflammation often appears in the eyes of children, but yields to proper remedies. Hence it may be imagined, that with attention the Egyptians would not suffer more than other nations.