The ship Belle Wood, Captain Tucker, arrived at Quarantine from Liverpool on Saturday evening, 6th inst., bringing nearly 700 emigrant passengers. During her passage there occurred on board six deaths, and on her arrival at Quarantine one corpse and fifteen cases of contagious disease were sent from her into the Marine Hospital.

The vessel and the remaining passengers were detained at Quarantine for cleansing, purification.

Yesterday, WILLIAM GALVIN and MARY, his wife, who had relations on board the Belle Wood, secured a small boat and put off to the sickly vessel for the purpose of having an interview with some of her passengers. As this was a violation of the Quarantine laws, the Metropolitan Policemen, stationed at Quarantine, were called in requisition to arrest the offenders. The officers promptly responded to the call, and before many minutes had elapsed, they brought WILLIAM GALVIN and MARY, his wife, prisoners to the wharf of the Health Officer. WILLIAM and MARY'S exposure to the contagion of the sickly vessel was such as to render their detention for a time necessary within the Quarantine enclosure.

DOMINIC RAGANS, too, was arrested on Sunday by the Metropolitan Policemen at Quarantine for carrying out sundry persons in a small boat to vessels under and subject to Quarantine, and for having intercourse and communication with their passengers. RAGANS is an old offender. He is well acquainted with the laws of the State in regard to Quarantine: and now that the season of yellow fever is at hand, when infractions of the Health laws may become a serious matter, it is to be hoped that Mr. RAGANS will be promptly tried, and so give others the benefit of his experience. He made many threats and much resistance to the officers who arrested him.

The Health laws of our port are very stringent. They do not permit persons in small boats to invade the Quarantine anchorage, much less to have intercourse and communication there with vessels and passengers: and now that the authorities at Quarantine have the aid of a sufficient number of Metropolitan Policemen, they have no excuse if they fall to deal summarily with offenders, who recklessly and willfully jeopardize their own lives and the public health.

If the Metropolitan Police law had been in force last Summer, the officers at Quarantine would have had the power to maintain a far more perfect isolation of persons from infected vessels and cargoes, and to save thousands of dollars worth of cargo which was stolen by river thieves.