— 63 — 
Comparative analyses of subsoil water in Egypt and Nile water in 
time of low supply are given below. 
Dissolved matter. 
PARTS IN 100,000 
Well water. 
Summer water 
in Nile. 
Lime.. 
16-56 
4-24 
Magnesia 
4-53 
1-00 
Soda 
. . 
8-20 
6-20 
Potash 
. . 
•37 
1-44 
Chlorine . . . . 
. . 
13*60 
-67 
Sulphuric acid 
5*93 
2-16 
Nitric acid 
•17 
— Traces 
Silica, alumina and oxide of iron 
, . 
. . 
1-80 
•97 
Organic Matters . . 
•60 
1-75 
Carbonic oxide and loss 
12-26 
4-03 
64-02 
22-46 
It must be remembered that Nile water in the time of low supply 
consists in a very appreciable part of subsoil water which has filtered 
into the Nile. 
Mr. Foaden states that, speaking in round numbers, we may say that 
Nile deposit in flood contains 
Nitrogen * 1 per cent 
Phosphoric acid *2 „ 
Potash * 6 „ 
He values the manure deposited by the Nile annually in a well 
irrigated basin at £‘75. He concludes that Nile water in flood is rich 
in potash, fairly rich in phosphoric acid and poor in nitrogen. 
27. The soil of the Nile valley. — According to numerous 
analyses made of Egyptian soil in 1872 by MM. Payen, Champion and 
Gastinel, the soil of Egypt consists of 
Silica 45 per cent 
Argile 53 „ 
Magnesia *2 to 1*6 ,, 
Lime 1 * 3 to 4 . 9 ,, 
Nitrogen *03 to *10 ,, 
Phosphoric acid. . . ... *03 to *32 ,, 
Some stiff soils contain 84 per cent argile and some light soils contain 
68 per cent sand. As one approaches the Mediterranean the quantity 
of chloride of soda increases and runs from a fraction to 4, 5, and even 
10 per cent. 
