See below 1851 census return for sailor John Irvine.
Piece: SCT1851/595 Place: Ayr -Ayrshire Enumeration District: 2
Civil Parish: Irvine Ecclesiastical Parish, Village or Island: Irvine
Folio: 0 Page: 20 Schedule: 100
Address: Hill Street
Surname First name(s) Rel Status Sex Age Occupation Where Born Remarks
IRVINE John Head M M 61 Hair Dresser Overseas - British - Island Of Antigua
IRVINE Janet Wife M F 46 Ayrshire - Irvine
IRVINE Elizebeth Dau U F 24 Sewer Of Muslin Ayrshire - Irvine
IRVINE John Son U M 21 Sailor Ayrshire - Irvine
IRVINE Shaw Mcfee Son U M 16 Porter Ayrshire - Irvine
IRVINE James Son U M 14 Porter Ayrshire - Irvine
Page: 0/21 IRVINE Janet Dau U F 9 Ayrshire - Irvine
IRVINE Andrew Son U M 7 Ayrshire - Irvine
WALLACE Agnes Reltiv W F 65 (Wife's Aunt) Rec. Par. Relief Ayrshire - Irvine
I know this will sound bizarre, but I have information that strongly implies that his father John Irvine (Hairdresser) was likely to have been a black slave at one time.