228 EGYPTIAN AGRICULTURE. 



Lime 3 '07 per cent. 



Magnesia 2 '68 



Oxide of manganese '25 



Iron oxide and alumina 25*56 



Phosphoric acid '25 



Carbonic acid '73 



* Organic matter, etc 8*82 ., 



(* containing nitrogen) ... *14 



These figures are quite consistent with the general 

 composition of Egyptian soils. If on the other hand, 

 Nile mud contained as high a percentage of phosphoric 

 acid as that given by Letheby and Wanklyn (1*78 per 

 cent), we should expect our soils to be phenomenally rich 

 in that ingredient, and while they are not poor, and con- 

 tain as a rule from '2 to '3 per cent, yet they are by no 

 means as extremely rich as would be expected were Nile 

 sediment so high in its content of phosphoric acid as 

 that indicated in the analysis referred to. Again, the 

 amount of organic matter given by Letheby and Wanklyn 

 (15 per cent.) is considerably higher than has been found 

 to be the case in the sediment at the time of flood, though 

 it exceeds this at the time of low Nile. The potash 

 given by these authorities (1 '82 per cent.) is also extremely 

 high. 



Assuming the analysis already reproduced to be ap- 

 proximately representative, the addition of 6J tons of 

 mud per acre containing *68 percent of potash, '21 per 

 cent of phosphoric acid, and '12 per cent of nitrogen 

 would add to the soils in the basins annually : 



Potash 99 Ihs. 



Phosphoric acid 30 -i .. 



17 i ,. 



