Yesterday, at the Martin Street Police Court, Antony Cowlrick was brought up for the seventh time, on the charge of being concerned in the mysterious murder which took place at No. 119, Great Porter Square. The remarks we have from time to time made upon this case and upon the arrest of Antony Cowlrick have been justified by the result. The prisoner was finally discharged. All that was wanted to complete the tragical farce was a caution from the magistrate to the prisoner not to do it again. We now intend to speak plainly; and the strong interest the case has excited will be our excuse if our comments are more lengthy than those in which we generally indulge in our editorial columns. The elements of mystery surrounding the awful murder were sufficiently complicated without the assistance of the police. Their proceedings with respect to the man calling himself Antony Cowlrick have rendered the task of bringing the murderer to justice one of enormous difficulty. Our business at present is not so much with the murder itself as it is with Antony Cowlrick and the police; but a brief recapitulation of the circumstances of the murder is necessary for the proper understanding of what is to follow. On Tuesday, the 1st of July, a gentleman engaged a back room on the first floor of the house No. 119, Great Porter Square. There was a piano in the room. The landlady of that house, who has undergone more than one lengthy examination, has stated that she "reckoned him up" as a man who had just come from a voyage, and that there was something superior "in the looks of him." When she asked him for his name he said it did not matter, and he handed her four weeks' rent, telling her at the same time not to trouble herself about a receipt. This was sufficient for the landlady; she received the stranger as a tenant, and he took possession of the room. He led a remarkably quiet life. He did not trouble the landlady to cook a meal for him, although "attendance" was included in the sum charged for the rent of the room. He had but one visitor, a lady, who came so closely veiled that no person in the house caught a glimpse of her face. She called three times, and when the street door was opened, asked for "the gentleman on the first floor," and went up to him without waiting for an answer. This lady has not come forward, and she has not been tracked. After the 10th of July no female resembling in the slightest the vague description given of her has called at No. 119, Great Porter Square.