Encyclopaedia Britannica > Volume 8, DIA-England

EGYPT.
517
ypt. themselves ; but the principal cause, he thinks, is the poor
and little nutritive food on which the natives are obliged
to subsist.1 The cheese, sour-milk, honey, confections of
grapes, green fruits, and raw vegetables, which are the or¬
dinary food of the common people, produce in the stomach
a disorder which physicians have observed to affect the
sight; and the raw onions, especially, which they devour
in prodigious quantities, have a peculiarly heating qua¬
lity. Bodies thus nourished abound in corrupt humours,
which constantly seek a discharge ; and, diverted from
the ordinary channels by habitual perspiration, these hu¬
mours fly to the exterior parts, and fix themselves where
they find the least resistance. They therefore naturally
attack the head, because the Egyptians, by shaving it
once a week, and covering it with a prodigiously hot head-
gear, principally attract to it the perspiration ; and if the
head receive ever so slight an impression of cold on being
uncovered, this perspiration is suppressed, and falls upon
the teeth, or still more readily on the eyes as being the
tenderest part. The ancient Egyptians, who went about
bareheaded, are not mentioned by physicians as having
been so much afflicted with ophthalmia as the modern;
and the Arabs of the desert, who cover their heads slight¬
ly, especially when young, are but little subject to this
disease. In Egypt, blindness is often the consequence of
small-pox; a disorder which, until lately, when vaccina¬
tion was partially introduced by Mehemmed Ali, used to
be very frequent and fatal. Another cause of this distem¬
per may perhaps be found in the fine impalpable sand
which is carried about by the wind, and also in the into¬
lerable brilliancy of the sunbeams reflected from a burn¬
ing and sandy soil impregnated with nitrous salt.
Besides these, there are two diseases less commonly
met with in Egypt; namely, a cutaneous eruption, which
returns annually, and a swelling of the testicles, which
often degenerates into an enormous hydrocele. The for¬
mer comes on towards the end of June or beginning of July,
making its appearance in red spots and pimples all over
the body, which occasion a very troublesome itching, and
is probably occasioned by the waters of the Nile, which
towards the end of April become putrid. The hydrocele
most commonly attacks the Greeks and Copts, and is at¬
tributed to the quantity of oil which they make use of, as
well as to their frequent hot bathing. In the spring sea¬
son malignant fevers occasionally prevail. In the treat¬
ment of these bleeding is found prejudicial, whilst vege¬
table diet, and bark in large quantities, have been found
useful.
We have already described the geographical configura¬
tion of the valley of the Nile, with its natural boundaries
consisting of two elevated ridges between which the river
flows for about a hundred and fifty leagues. These moun¬
tain chains are on many accounts highly deserving of atten¬
tion, but on none, perhaps, more than by reason of their
geological structure and characters. After passing through
a district of primitive formation, they enter that of the se¬
condary and floetz-trap kind, and terminate in deposits be¬
longing to the most recent species of stratified rocks.
The granite or southern district extends from Philce to
Assouan, in 24° 8' 6" N. and 33° 4' E., and consists for the
most part of syenite or oriental granite, in which may still
be observed the quarries whence the ancient Egyptians Egypt,
detached the stupendous monoliths required for their co-
lossal statues and obelisks. The granite is occasionally
diversified by alternations of gneiss, porphyry, clay-slate,
quartz, and serpentine, erroneously described as a green-
coloured marble, containing imbedded in them a variety
of carnelians and jaspers; and there has also been observed
in this district a granular foliated limestone or marble,
exhibiting various hues, as white, grey, yellow, blue, red,
and, when combined with serpentine, forming the rock
known by the name of verde-antico. From the quarries
of Philce, Elephantine, and Syene, were obtained the beau¬
tiful oriental or rose-coloured granite, called syenites by
Pliny, from the place near which it abounded, but differing
from the syenite of modern mineralogists. In this rock
two thirds of the mass consists of felspar, varying in colour
from a pale pink to a brick red ; and the remainder is com¬
posed of mica exhibiting a metallic lustre, and diaphanous
quartz, with sometimes a small quantity of hornblende, in
which case it becomes the syenite of Werner. Pliny de¬
nominates it Thebaic stone, not from there having been
any quarries of this rock in the neighbourhood of Thebes,
but from the frequency of its occurrence in the gigantic
monuments of the ancient capital of Egypt. The rose-
coloured variety seems chiefly confined to the vicinity of
Elephantine, though it is also found unmixed for some
distance on both sides of the river. As syenite is con¬
nected by numerous shades and gradations both with the
common granite and also with the succeeding species of
rock, so we have accordingly the granitello of lapidaries
when it is fine grained,' grey syenite when the felspar is
of that colour, black and white granite when the felspar
is white and the mica black, and Egyptian or oriental ba¬
salt when it has been extracted from veins in which the
mica and hornblende prevail in black homogeneous masses,
with scarcely any admixture of felspar. The hardness of
this stone is such as to preserve its surface uninjured by
exposure to the atmosphere. But the remarkably perfect
state in which the monuments of Egypt are found ought
perhaps to be ascribed to the uniform dryness of the air,
and the almost total absence of rain; and this is rendered
more probable by the circumstance, that in the Delta, es¬
pecially near the sea, where showers occasionally fall, and
the atmosphere is charged with a greater quantity of mois¬
ture, the process of decomposit ion has commenced, and in
some places made considerable progress.2
Between Assouan and Esneh, in 25° 19' 39" N. is the
argillaceous sandstone or middle district, which supplied
slabs for most of the temples ; and beyond it the northern
or calcareous district stretches to the southern angle or
vertex of the Delta. At Esneh, indeed, the rocks assume
the calcareous character, and retain it until they merge
into the plain below Cairo, at the southern limit of the
lower division of Egypt. From this last chain were quar¬
ried, not only the solid part of the Pyramids, but also ma¬
terials for many public buildings, which, as they proved
excellent stores of lime and stone for the Arabs and other
barbarians who for so many centuries desolated Egypt,
have long since been destroyed. The steep perpendicular
cliffs of this limestone formation impart to the portion of the
country where it prevails a hard and monotonous aspect,
1 This is no doubt one cause of the distemper; but liifaud has shown that there are others. “ On a attribue' la frequence des
ophthalmias en Egypte aux vents qui soufflent periodiquement; je croirois plutot pouvoir trouver la cause de cette maladie dans
1 habitude ou sont les Egyptians de coucher sur les terrasses pendant neuf mois de 1’annee- II faut considerer que les campagnes de
1 hgvpte sont d’immenses plaines, oil la lumiere est tres vive ; leur terrain est sec, friable, et brulant, particulierement en ete ; il est
argilleux et crayeux, contenant le nitrate de potasse, le natron, et le muriate de soude. D’ailleurs, les jours sont d’une chaleur ex¬
cessive, tandis que les nuits sont fraiches, humides, et nebuleuses. Ces circonstances physiques reunies ne peuvent agir sur 1’organe
de la vue sans y causer des desordres. On a remarque que les ophthalmies sont plus communes en ete qu’en hiver, et que les ani-
niaux y sont sujets aussi-bien que 1
* Encyclopaedia Metropolitana, art.
Egypt.