LANDSCAPE GARDENING AND RURAL TASTE.--A correspondent has elsewhere touched upon these themes, and we are glad to perceive that they are attracting something of public attention. The want of taste of which the writer complains, is but too general. Propriety and beauty of location, in our cities, even, are often sacrificed to the mere external ornaments of the edifice itself. Speaking of a picturesque and pleasant mansion near London, COOPER sarcastically observes: 'We should pull the building down, if we had it in New-York, because it does not stand on a thoroughfare, where one can swallow dust free of cost.' There is a good deal of truth in this. A superior house may not unfrequently be seen here also, occupying, by choice of the owner, some such 'cheerful position' as KNICKERBOCKER's hotel, which 'commanded a pleasant view of the rear of the poor-house and bridewell, and the front of the hospital.' Our country-seats, too, are still sometimes chosen, as formerly, if we may believe our venerable foster-father, the pleasant _locale_ being often 'on the borders of a salt marsh; subject, indeed, to be occasionally overflowed, and much infested in the summer-time with musquitoes, but _otherwise_ very agreeable,' producing abundant crops of salt grass and delicate bulrushes. In England, says IRVING, the rudest habitation, the most unpromising portion of land, in the hands of a person of taste, becomes a little paradise. 'The sterile spot grows into loveliness under his hand; and yet the operations of art which produce the effect are scarcely to be perceived. The cherishing and training of some trees; the cautious pruning of others; the nice distribution of flowers and plants of tender and graceful foliage; the introduction of a green slope of velvet turf; the partial opening to a peep of blue distance, or silver gleam of water--all these are managed with a delicate tact, a pervading, yet quiet assiduity, like the magic touchings with which a painter finishes up a favorite picture.' What might not portions of America be made, under the influence of similar action? * * * * *