A term used by tradesmen for bartering the different commodities in which they deal. Thus a hatter furnishing a hosier with a hat, and taking payment in stockings, is said to deal blood for blood.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Blood * Blood MoneyNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes