White Blood explores how the nature and properties of human breast milk were conceived within the fluctuating frameworks of distinct historical periods. For example, in the ancient world, human milk was thought to be blood diverted from the womb to the breast, where it was whitened and vivified to nourish the newborn. In the Renaissance it became known as a vital fluid transmutable into flesh by an "internal alchemist"; in the Enlightenment it was said to flow from "nature's bountiful urn."

From ancient Greece and Rome to the present, Lawrence Trevelyan Weaver traces the historical past of human milk across centuries, noting how the cultural and historical frameworks of the past informed the practices of milk feeding and its effects on infant health, growth, welfare, and survival.