Algernon Skinner, 78, of 9 Hancock Avenue, died of gangrene in a leg Thursday at the Medical Center, where he had been a patient since November 7. The funeral was to be held today. He was born in Port Orange, New York, where he been a farmer until his retirement 20 years ago, when he moved to Jersey City. Mr. Skinner is survived by his wife. Mrs. Nora Skinner nee Piatt; his sons. George and Robert Skinner; his daughters. Mrs. Winifred McManus and Mrs. Florence Freudenberg. and a stepdaughter. Mrs. Nora Freudenberg.