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.
From the means of ten samples of soil from Kena Mudirieh analysed for me in May by Mr. Frank Hughes of the Agricultural Society we gather that the constituents of the soil are as follows:—
| Ingredients. | Max %. | Min %. | Mean %. |
|---|---|---|---|
| Silica etc., insoluble in strong acid | 66 | 53 | 60 |
| Total Lime | 3·80 | 2·50 | 3·34 |
| Total Potash | 1·19 | ·46 | ·74 |
| Total Potash available | ·072 | ·020 | ·042 |
| Total Phosphoric Acid | ·49 | ·20 | ·35 |
| Total Phosphoric available | ·090 | ·029 | ·066 |
| Carbonic Acid = Chalk | 3·52 | 1·79 | 2·69 |
| Nitrogen | ·106 | ·056 | ·084 |
We have here a general sufficiency of phosphoric acid, plenty of potash and lime, and a low proportion of nitrogen.