253 



rotten manure. In Egypt from 7 to 8% may be taken 

 as an average of old manure. Calculated to dry matter, 

 English manure heaps contain about l% of organic 

 matter and Egyptian heaps similarly 8 or $%. The 

 former contains in one ton from 9 to 15 Ibs. of nitrogen, 

 about the same quantity of potash, and from 4 to 9 Ibs. 

 of phosphoric acid (Warington).* Egyptian farm-yard 

 manure is thus poorer in organic matter, nitrogen and 

 phosphoric acid but much richer in potash. In one ton 

 the nitrogen is equivalent to approximately 45 Ibs. of 

 nitrate of soda, the phosphoric acid to 27 Ibs. of super- 

 phosphate (16-18^ soluble) and the potash to 61 Ibs. of 

 purified sulphate of potash. That a value attaches to such 

 bulky substances in addition to what is actually represented 

 by the percentage of valuable ingredients they contain has 

 already been referred to, and an application of chemical 

 manures containing equal amounts cf nitrogen, phosphoric 

 acid and potash would by no means have the same 

 ultimate effect in the soil. 



It is a fact well recognised by native cultivators that a 

 dressing of farm -yard manure is periodically necessary to 

 keep up and maintain the fertility of the soil. Coufri, 

 which will be referred to later, is extensively employed 

 for maize, grain, and other crops, but it is accepted that 

 a continuation of its use rapidly reduces the condition of 

 the soil and good cultivators are adverse to its too extensive 

 employment. In cotton cultivation, the employment of 

 farm -yard manure is attended by most satisfactory results, 



\V ATUN<;TO\"S " < 'Ix'mistrv of tli i> Fiii'in. " 



