NEWBOLD ON THE GEOLOGY OF EGYPT. 34] 
ving almost in their original freshness, its magnificent sculptures and 
vivid frescos. Schorl, black and green, and actinolite are minerals 
occasionally found in the granite of Upper Egypt, as well as the chry- 
soberyl. Native gold* and iron ore are found near its junction with 
hypogene schists, in the Beshariyeh hills about ten days’ journey in 
the eastern desert from Edfou. 
Economical Uses+.—Most of the colossal statues, sarcophagi, 
columns and obelisks of the ancient Egyptians were quarried from this 
rock at Syene; and it was likewise applied to lining both the exterior 
and interior of the pyramids. 
Alluvial Soils: Classification and Extent.—The alluvial soils of 
Egypt may be divided into four classes: Ist, the mud of the Nile 
and delta ; 2nd, the soil of the Oases, resulting principally from the 
successive decay and reproduction of vegetation mixed with sand and 
marl; 3rd, detrital soil of circumscribed extent washed down from the 
rocks ; and 4th, a greyish soil, which is found generally around the 
ruins of old cities; the result of decayed animal and vegetable matter, 
mixed with fragments of limestone, mortar, and other debris of the 
crumbling buildings. The nitric acid, disengaged from the animal 
matter combining with the vegetable or mineral alkalis, forms impure 
nitrates of potash, soda and lime. Both ammoniacal and nitrous 
salts are formed in certain places in the desert where camel-caravans 
usually halt ; their presence is denoted by dark moist-looking patches 
on the surface, caused by the deliquescence of these salts, which have 
from the earliest times been collected and purified by the Egyptians. 
Nature of the Mud of the Nile.-—The mud of the Nile, as has 
been observed already of the sands of the desert, is slightly modified 
in character at various localities, according to the nature of the for- 
mation over which the Nile flows during its course to the sea. Above 
Thebes, below the granite and sandstone formations of Nubia, and 
‘on the southern limit of Egypt, it contains more silex and less cal- 
careous and argillaceous matter than at Cairo and the delta, which 
are situated on the great limestone formation. The mud of the Nile is 
not the result of the spoils of Abyssinia alone, and hence, perhaps, the 
discrepancy of the analyses we possess of it. That of Regnaultt, 
which appears to have been the most minute, is as follows :— 
hi LAE abe laud ee A a ae sate i 
TSE ae a eae ei ap ie 9 
Micador Won ye 8 
Bes ee Oe oY ee 
Carbonate of magnesia...... 4 
Carbonate of lime ........ 18 
PAMIOMEIBISECE 3 oe ee Ree ee Sees 48=100. 
* Gold-mines, according to Agatharcides, quoted by D’Anville, exist in the Ataka 
range on the coast of the Red Sea, about lat. 22° N., but the nature of the forma- 
tion is not stated. 
t For details regarding the method of quarrying this rock and its sculpture, vide 
my paper on this subject read before the Royal Asiatic Society. 
~ Regnault, Mémoires sur |’Egypte, tom. i. pp. 348, 382. 
VOL. IV.—PART I. 26 
