272 EGYPTIAN AGRICULTURE. 



On the other hand the injurious effects of the salts 

 present in the tafia have to be considered as well as the 

 fact that the continued use of this manure leaves a consi- 

 derable quantity of stony material on the land, and 

 considerably hardens the soil. On several occasions the 

 question has been discussed as to whether it would be 

 advantageous to transport tafia to Lower Egypt. Unless 

 the material can be found in bulk of a much better quality 

 than that actually being used, it would not be profitable 

 to do so. 



MAKOG. 



The uncultivated land situated between the river and 

 the hills in Upper Egypt, between Luxor and Assouan, 

 is often covered by a deposit of material possessing consi- 

 derable mammal value. This material, which is known 

 as " marog " is extensively employed for manuring the 

 millet and cereal crops. The plains have been more 

 or less dug over by small cultivators, and an immense 

 number of donkeys and camels may be seen transporting 

 this material to the fields. 



It is probable that the surrounding hills being rich in 

 tafia the salts have been brought down by rain and 

 distributed there over the plains. The material consists 

 of earthy matter mixed with salts in various proportions. 



The salts present consist of chloride, sulphate, and 

 nitrate of sodium. It is to the presence of the last named 

 that the manurial value of the material is due. 



It is as a rule richer than coufri, as the following 

 analyses from the plain of Kom Oinbo will show. 



