Feeding babies is a topic of intense concern to mothers and of great interest to public health professionals. Milk has been the life and death of the newborn, and their fortunes have often turned on whether they were fed naturally or artificially. 'Breast is Best' has been the consensus view throughout history but, for choice or necessity, other ways of feeding infants have been used: wet nursing and so-called 'dry nursing', 'hand feeding' or 'bottle-feeding'. 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 a vital fluid transmutable into flesh by an 'internal alchemist'; in the Enlightenment it flowed from 'Nature's Bountiful Urn'; in the eighteenth century it was a corpuscular liquid formed of 'combustible, plastic and oily parts'; in the nineteenth a chemical formula made up of carbohydrates, proteins and fats; and in modern times a biological fluid composed of macro and micro-nutrients, trophic factors, immunoglobulins and living cells - a live substance, akin to that of the Ancients. White Blood explores the ways in which the nature and properties of milk have been conceived within the fluctuating frames of thought that characterised the historical periods of the past. From shifting viewpoints it charts the effects of changing practices of milk feeding on infant health, growth, welfare and survival. Starting in ancient Greece and Rome, White Blood lets the voices of those concerned with the care of newborn infants, and those who followed them, speak across the centuries of how babies were, and should best be, nourished.