50 THE ANCIENT EGYPTIANS. CHAP. XI. 



the surface ; a custom continued to the present day : 

 but this was confined to certain crops, and principally 

 to those reared late in the year ; the fertilising pro- 

 perties of the alluvial deposit answering all the pur- 

 poses of the richest manure. * Its pecuhar quality 

 is not merely indicated by its effects, but by the 

 appearance it presents ; and so tenacious and sili- 

 cious is its structure, that when left upon rock, 

 and dried by the sun, it resembles pottery, from 

 its brittleness and consistence. Its component 

 parts, according to the analysis given by Regnault 

 in the "Memoires sur I'Egypte*," are — 



11 water. 



9 carbon. 



6 oxide of iron. 



4 silica. 



4< carbonate of magnesia. 

 18 carbonate of lime. 

 48 alumen. 



100 



the quantity of silica and alumen varying ac- 

 cording to the places whence the mud is taken, 

 which frequently contains a great admixture of sand 

 near the banks, and a larger proportion of argil- 

 laceous matter at a distance from the river. 



The same quality of soil and alluvial deposit 

 seems to accompany the. Nile in its course from 

 Abvssinia to the Mediterranean ; and though the 



* Cor>f. Plin. xviii. 18. " Niliis ibi coloni vice fungens." Macrobius 

 attributes the use of manure to Saturn. Lib. i. c. 7. 

 ■f Tome i. p. 351. 



