The quarantine ground of the port of New-York, which is on the north-eastern point of Staten Island, five and a half miles from the Battery, is admirably located for the purposes of purification, and liberally endowed with all the necessary means for the cure of the sick and the prevention of the spread of disease. The ground appropriated for the purposes of a lazaretto has a frontage on the bay of about fourteen hundred feet, and extends back twelve hundred feet. It is inclosed by a high brick wall, and includes suitable hospitals for the accommodation of the sick, houses for the resident physician, and offices for the numerous persons employed about the grounds. The largest hospital, appropriated for fever patients, is that nearest the water. It is constructed of brick, is three stories high, and one hundred and thirty-six feet long by twenty-eight feet wide. The building on the rising ground next above this is intended for convalescents. It is built of brick, three stories high, fifty feet long, and forty-five feet high, with two wings sixty-six by twenty-six feet each. Higher up, beyond this, is the small-pox hospital, which generally has the largest number of patients. It is but two stories, eighty feet long and twenty-eight feet wide; like the other hospitals, it is built of brick, and has open galleries on the outside, in front, and rear. The quarantine hospitals, although forming no unimportant part of the maritime institutions of New-York, do not properly come under the head of those denominated benevolent, as they are merely sanitary and for the purpose of preventing the spread of contagious diseases. [Illustration: THE SEAMEN'S RETREAT.]