Our own districts of the N.W.Provinces, which intervene between those north of the Ganges and Rajpootana, have the advantage of rivers and canals; but their atmosphere is not so well supplied with moisture from the sea, nor are they so well studded as they ought to be with trees.

The Punjab has still greater advantages from numerous rivers, flowing from the Himmalaya chain, and is, like Egypt, in some measure independent of moisture from the atmosphere as far as tillage is concerned; but both would, no doubt, be benefited by a greater abundance of trees.

They not only tend to convey to and retain moisture in the soil, and to purify the air for man, by giving out oxygen and absorbing carbonic acid gas, but they are fertilizing media, through which the atmosphere conveys to the soil most of the carbon, and much of the ammonia, without which no soil can be fertile.

It is, I believe, generally admitted that trees derive most of their carbon from the air through their leaves, and most of their ammonia from the soil through their roots; and that when the trees, shrubs, and plants, which form our coal-measures, adorned the surface of the globe, the atmosphere must have contained a greater portion of carbonic acid gas than at present.

They decompose the gases, use the carbon, and give back the oxygen to the atmosphere.
_December_ 30, 1849 .-- Ten miles to Salone, over a pretty country, well studded with fine trees and well tilled, except in large patches of oosur land, which occur on both sides of the road.