1845.] Diluvial and Wave Translation Theories. 231 



This I also remarked to be the case with the mud of the Nile, par- 

 ticularly in the upper parts of its course through Egypt : but on the 

 Delta where the slope of the bed is still less, and the motion of the 

 stream languid, the stratification is more obscure. 



Both in the mud of the Nile, and in that of the tanks of India 

 where annual layers of deposition may be strongly marked, the 

 layers of monthly, weekly or daily deposition are indistinct or not 

 to be traced ; hence the interior of the annual layer individually has 

 an unstratified appearance. The same is observable in the structure 

 of some individual beds of enormous thickness, as in the thick-bedded 

 sandstones, in which, if the particles are of a homogeneous nature, 

 stratification is hardly visible even on the face of cliffs 200 or 300 feet 

 high. 



It is possible that the regur, which is often thirty feet thick, 

 from its generally unstratified aspect and homogeneous character — 

 containing no interstratified layers of sand or pebbles, was the result of 

 one period of deposition. In areas where stratification is said to be 

 more distinct, for instance in Baroche, the deposit has probably under- 

 gone rearrangement by subsequent currents. It is just such a de- 

 posit as might be expected to result from deep waters charged with 

 the debris both mineral and vegetable of a submerged continent, 

 the coarser and heavier fragments of which, as well as the silts and 

 sand, had been deposited or left behind by the slowly retarding 

 current. At length, as the waters gradually gained their level, the 

 turbid fluid, now charged with nothing b.ut the very finest and light- 

 est particles, would move so slowly as to admit of their gradually 

 sinking and being deposited on its bed. Above the first cataract and in 

 Upper Egypt, where the current is more rapid, the deposit is usually 

 of a coarse, and more silty nature than in Lower Egypt and on the 

 Delta, and not of so carbonaceous a nature. Many of the finest par- 

 ticles are never deposited at all by the Nile in Egypt, but are carried 

 out with its waters, and discolour the Mediterranean upwards of 70 

 miles from its embouchure. The sea water from its great specific 

 gravity adds to the obstacles against deposition. The deposit of the 

 Nile in some parts, as well as those of some tanks in India, not only 

 resembles the regur in external appearance and colour, but also in 

 chemical character. All three contain a considerable portion of vegeta- 

 ble matter. 



