LET me specialize a visit I made to the collection of barrack-like one-story edifices, Campbell hospital, out on the flats, at the end of the then horse railway route, on Seventh street. There is a long building appropriated to each ward. Let us go into ward 6. It contains to-day, I should judge, eighty or a hundred patients, half sick, half wounded. The edifice is nothing but boards, well whitewashd inside, and the usual slender-framed iron bedsteads, narrow and plain. You walk down the central passage, with a row on either side, their feet towards you, and their heads to the wall. There are fires in large stoves, and the prevailing white of the walls is relievd by some ornaments, stars, circles, &c., made of evergreens. The view of the whole edifice and occupants can be taken at once, for there is no partition. You may hear groans or other sounds of unendurable suffering from two or three of the cots, but in the main there is quietalmost a painful absence of demonstration; but the pallid face, the dulld eye, and the moisture on the lip, are demonstration enough. Most of these sick or hurt are evidently young fellows from the country, farmers sons, and such like. Look at the fine large frames, the bright and broad countenance, and the many yet lingering proofs of strong constitution and physique. Look at the patient and mute manner of our American wounded as they lie in such a sad collection; representatives from all New England, and from New York, and New Jersey, and Pennsylvaniaindeed from all the States and all the citieslargely from the west. Most of them are entirely without friends or acquaintances hereno familiar face, and hardly a word of judicious sympathy or cheer, through their sometimes long and tedious sickness, or the pangs of aggravated wounds.