THE SLAINS CASTLE. First of the arrivals in the year 1841 was the fine River-built ship Slains Castle, which came into port on January 25th, after a passage of 133 days, having sailed from Gravesend on September 14th, 1840. She was a vessel of 500 tons, and was commanded by Captain James Petrie. There were 224 passengers on board, including Mr. Octavius Carrington [Augustus Octavius Crocker Car...