JAN.— -MAR. 1858.] 



The Royal Society. 



253 



On examining the results of ninety-five excavations and prob- 

 ings of the alluvial land, it appears : — 1. That the alluvium is of 

 two principal kinds : first and chiefly, an argillaceous earth or 

 loam, more or less mixed with fine sand of various shades of color, 

 being the true Nile mud or sediment ; and, secondly, pure quart- 

 zose sand, derived in a great measure from the desert, which is 

 swept by violent winds through the gullies in the hills on either 

 side, but chiefly from the Libyan range. 2. That the Nile sedi- 

 ment found at the lowest depth reached, is very similar in com- 

 position to that deposited by the inundation water of the present 

 day. 3. That in no instance did the boring instrument strike 

 upon the solid rock which may be presumed to form the basin 

 between the Libyan and Arabian hills, which contains the alluvium 

 accumulated through unknown ages, from the time when this de- 

 pression in the earth's surface was formed, and the waters of the 

 Nile first flowed through it. 4. That except minute organisms 

 discoverable only by a powerful microscope, few organic remains 

 were met with, and that those forms were recent land and river 

 shells, and bones of domestic animals. 5. That there has not 

 been found a trace of an extinct organic body. 6. That at the 

 same levels great varieties in the alluvium have been found in ad- 

 joining pits, even when the distances between them are very mo- 

 derate. 7. That there is an absence of all lamination in the 

 sediment. When the author first undertook these interesting 

 researches, he expected that sediment, slowly deposited on the 

 land from nearly tranquil water, would present in sections a lami- 

 nated structure — more especially as an able observer, the late 

 Captain Newbold, stated that he had met with such an arrange- 

 ment of the alluvial soil. It was therefore with no small surprise 

 that on examining the soil from the excavations at Heliopolis, no 

 such laminae could be discovered, and in none of the excavations 

 or borings has such a structure been met with in a single instance. 

 There can be no doubt that a layer of sediment must be deposited 

 upon the land, but as soon as the waters have subsided, the sun, 

 the wind, and cultivation combine to break it up. From the 

 earliest times when the Nile Yalley was inhabited by man, the 



