Fairly plentiful still in Egypt, there must, of course, be a limit to this supply. The taking up of land is going steadily on, and consequently the remains of city after city have been and are being rapidly used up, thus necessitating the establishment of plans upon a practical basis for the restoration of land which should not be exhausted by heavy crops without the cultivator making a proper return. One of our students of agriculture, in a public address, deals largely with the necessity for the dissemination of a practical knowledge of the needs of the land. He speaks of the great waste of fertilising matter in the way in which the refuse stalks of two of the greatest crops of the Delta--cotton and sugar-cane--are burned in the furnaces of engines, for which purpose they are most valuable when it is taken into consideration that fuel wood is a rarity and coal a luxury of exorbitant price. But after burning, so ignorant have the people been, that the tons upon tons in the aggregate of this rich ash from the engine fires which consume the refuse of the enormous crops of sugar-cane annually grown, have been looked upon as comparatively valueless, in spite of the fact that the ash contains almost all that is required for the growth of so exhaustive a crop, and it has been either cast away or sold for a trifle, to be used up in the manufacture of bricks. He adds, in words full of pregnant meaning, that even the fertile alluvium of the Nile Valley cannot long sustain this treatment without exhaustion, in spite of the much that is done by the feeding off and ploughing in of the leguminous crops, which play a great part in giving back what has been taken away. Farms here, too, are often found with a large dovecote, as alluded to in the description of the Khedive's estates; for the Egyptian cultivator has a fine substitute for the guano of the Peruvian Chincha Islands in that of the pigeons which are kept in flocks for the sake of this strong fertiliser. Undoubtedly they must take severe toll from the crops, whether green or fit for harvesting, though perhaps this is counterbalanced by the fact that the birds must gain a good subsistence upon the grain that would be wasted or go back to the soil, so much being shed at ingathering time in consequence of the heat. This carefully-saved fertiliser is used by the Egyptian for applying to vegetables and such productions as water melons and other plants of the gourd family, which depend much for their size on stimulation.