Royal Society. ±qq 



The results of the analyses are given by the author and ft* 



?s,Z Xr~ ns ° f Niie L < *™ «* -Ss^ 4 * 



Silica. 54-585 



Sesquioxide of iron 20 - 215 



Sesquioxide of alumina "." 6 "4 IS 



Alumina 5*237 



Carbonate of lime 3717 



Sulphate of lime 0245 



^j me --. '.'.;::; 1.912 



Magnesia . 762 



Potassa n-<~o 



ooda n.r -o 



r. . oo3 



Organic matter 5'701 



99-818 



In order to ascertain the amount of solid matter held in *u«nen«ion 



bot ?VT e H r ° f , the ST* near Cair °' the author d «**° 3 t Dr "Ab- 

 bott, a resident in that city, the method he had followed in 1832 to 



Rl ineTV" am T ° f S0U , d f att6r SU ^ ended in the water of the 

 Khine at Bonn, and requested him to undertake the experiment on 



mpenal gallon. I he residuum sent was analysed at the Royal Col- 

 lege of Chemistry, and yielded very nearly the same result as to com 

 position as the above average analysis of the Nile sediment 



On examining the descriptions of the soils sunk through in the 

 nine excavations at Hel.opolis, it appears that they consist of two 

 principal kinds, viz earths and sands. The earths vary in colour bS 



ZeTZJ ^ ^'^ bj? SUCh b8ensible «***» «to each 

 other, and having so great a resemblance to the modern Nile sedi- 

 ment that they may all be classed as Nile mud. The sands are 

 almost entirely pure quartz, similar to those of the adjoining deserts 

 In the same horizontal plane, even in this limited space of half a 

 square mile there is a very considerable difference in the nature of 

 he soi , and in none of the excavations was there an instance of 

 lamination in the deposit. "muwcb or 



nnSv bAr^T?- h ° W SmaU ^ the amount of scdiment kft 

 annually by the inundations in any one place, it is very difficult to 



conceive, in the author's opinion, how there should beh any one 



ZcZ S " 5£ 0M " i aS ^ feCt ° f °" e kind of -diment'as is 

 the case ,„ one of the excavations, without anv lamination or other 



STJ , t v SUCCeSS1Ve 1 dep0S 1 iti0n ' and «""! more "inconceivable that in 

 pits within a very short distance of each other different kinds of soil 

 should be found at the same levels. Other causes than the tran- 

 quil deposit from inundation water must have been at work in the 

 formation of this portion of the alluvial land. The layers of sand 

 were most likely blown across the valley from the desert. 



I he author deems it advisable to abstain from general remark* 



