This peculiarity in the circumstances of Egypt, must be accounted for by natural causes ; and though we cannot pretend to detect every arrangement which tends to produce so striking an effect, yet there are certain causes obvious to reflecting and philosophical minds, which are sufficient to spew in what manner this occurrence takes place. " The tendency of the air," from the cooler regions, " to fill up the rarefied space between the tropics, not only produces the monsoons and trade winds, but also assists us to offer a reason for the deficiency of rain in the districts of Egypt. Being partly within the extent, and altogether within the in fluence of the northern monsoons, the clouds of that quarter are hurried toward the equator from the month of April to October, and, being carried both rapidly and high, none of them descend upon Egypt, where there are no lofty mountains to attract them, nor do they let fall on its surface any part of their burden, but leaving it unvisited and dry, they hasten to the moun tains of Abyssinia, and there deposit their watery stores. The heated and rarefied air between the tropics neces sarily ascends into the higher regions of the sky ; and, yielding to the thicker atmosphere, by which it is dis placed, it is driven towards the northern mountains to be loaded with vapours, and to return in a lower direc tion toward the equator." (Dr Wilson's History of Egypt, vol. i. p. 19. and 20.) But though rain seldom falls in Egypt, yet the dews are exceedingly copious, and refresh the ground.
The comforts of Egypt are diminished, by being sub ject, in some degree, to that suffocating wind of the deserts, which spreads terror and desolation. It is call ed the sunzie/, the sinzoom, and the chamsin. It is an nounced by a lowering, troubled sky, and sometimes by a hissing noise. Its heat may be compared to that of a newly opened oven, and its effects are always dis tressing, and sometimes insupportable. It hardens the skin, and destroys the vegetable growth. It affects the lungs by its pernicious qualities, produces convulsions, and sometimes death. It is felt in Africa, India, Syria, and Arabia ; and it reaches Italy in a more modified condition, where it is called the sirocco, and is guarded against with anxiety and care.
Every where the human race are subject to diseases, and in Egypt some of them appear in their worst forms. The leprosy, with which the people of that country are frequently affected, does not seem to he so virulent as that which was spoken of in old times. But the diseases of the eyes are violent and dangerous ; and a considerable part of the people are occasionally affect ed, and sometimes so severely, that some of them lose one, and others both of their eyes. The British soldiers brought this disease with them to Europe ; and it is to be hoped that the attention of our experienced surgeons has paved the way for moderating the dangers of the disease. The sources of this affection are not well as
certained, though it has been supposed, that it is owing to the small dust with which the air is impregnated, and especially to the nitrous particles with which the soil of Egypt abounds. It may partly be ascribed to the habit of sleeping in the open air, and being expo sed in the day time to the excessive glare of the reflect ed sun. Guarding against these inconveniences, will promote the health and comfort of the inhabitants. But of all the diseases which affect this or any other coun try, the plague is the most alarming. Like other fevers, it is supposed to proceed from miasmata, or putrid efflu via, and it spreads its infectious matter in the air. A high degree of heat, as well as the application of cold, is said to abate its violence, and remove its effects. It has frequently been found, that the free access of cold air has removed the symptoms ; and we have no doubt that using the cold bath would be found to be effica cious.
There is no room for mineralogy in the district of the Delta, nor does the valley of the river, in any part of its course, afford subjects for the investigation of that science; but the mountains and higher grounds on each side of the river, yield many curious specimens of the fossil _kingdom. The rocks, which form the banks of the lower part of the Nile, are all calcareous, and those on which the pyramids stand abound with shelves, but above the town of Esnah they consist of freestone of various qualities. The chain of mountains on the right, or Arabian side of the river, furnish granite, pe trosilices, porphyry, and traps. Here too are found pudding stones, and various kinds of breccia. It was a species of the pudding stone of which the colossal statute of Memnon was formed at Thebes, which, ac cording to ancient tradition, emitted various sounds at the rising or setting of the sun. Granite or primitive rocks are found in Egypt, but they chiefly prevail to ward the southern parts of the country. One of the mountains toward the Red Sea, is called the Mount of Emeralds, and precious stones had formerly been ob tained from that part of the country ; for those of the best quality are still called by the Persians, the emeralds of Alsaid. Among the fossil specimens of Egypt are found felspar, hornblende, lapis-ollaris, marble with veins of silver, mica, amethyst, calcedony, carnelian, onyx, jasper, swinestone, &c. In the isthmus of Suez there are various silicious fragments, which serve as a bed for those curious Egyptian pebbles, which, when cut, exhibit portraits, branches of trees, ruined build ings, and other imitations of nature. Egypt does not abound in metals, yet iron as well as manganese has been found there, and it is obvious that lead and cop peer had formerly been worked in its mines.