Wet Nurses, Microbes, Milk-siblings: Milk as Liquid Conduit

15.01.2021

Milk impregnated the particular atmosphere of women. According to Bordeu, milk was subject to a process of ceaseless ebb and flow; “our women sweat milk, urinate milk, chew and sneeze milk, and they pass it in their stools.” Milk could even flood the womb.’ (Corbin, 1986: 36)

The story goes that Saint Agatha of Sicily refused to renounce her faith even after her breasts were cut off during torture. The patron saint of rape victims, breast cancer patients, wet nurses, and bellfounders (due to the shape of her severed breasts), Agatha is often depicted holding her amputated parts on a plate in front of her, as if offering them to a guest. In Sicily, Agatha is celebrated with breast-like cakes served on silver platters.

I summon Saint Agatha to evoke breasts separated from bodies offering nourishment; nipples, teats, interfaces, nurturing membranes, the architectures of lactation separated from the body. The image of Saint Agatha can be read as an image of an unprivatised breast, divorced from a specific body and offering itself up to no-one in particular.

White Blooded Mammals

Being a lactating human makes one painfully aware of what it is to be mammal. As a species our bodies are expensive to run; hungry, sweating, blinking, leaking, breathing, constantly metabolising entities, just regulating our warm blood takes a huge amount of energy. The word ‘mammal’ defines us through our need for, and ability to produce, milk. In turn our infants need for milk dictates a profound evolutionary bond that further shapes our species.

Seeking milk is innate and deeply programmed. When newborn babies are placed on their mothers stomach directly after birth they will navigate using smell, swimming their arms and legs until they reach the nipple (a skill shared by all young mammals). Nipples exude the odour of amniotic fluid – the only smell familiar to a newborn which they will gravitate towards.

Innate as it may be, lactating challenges the pace of contemporary human life; it does not follow work schedules, leaks unpredictably through shirts during meetings and on public transport. To have a lactating body is to experience some other tidal sense of time, to be plugged into an oceanic, milky current.

The body melts fat and turns it into milk. Lactating mammals, therefore, are essentially feeding their infants a part of their own bodies. If a human has been vegetarian since adolescence the animal protein they ate as a child is stored in their body, if they then have a baby these reserved proteins are liquified into their milk. Milk is, therefore, quite literally fluid communication, a digestible conduit for the world the baby will enter. What the lactating person eats seasons their milk, making it spicy, sweet, garlicky; the baby learns the tastes of the culture it will enter into before ever eating solid food.

This communicative capacity of milk does not only work from breast to baby; when babies suckle they create a vacuum so that some of their saliva is sucked back into the nipple. Within the nipple special glands scan the saliva for any signs of foreign germs. If the baby is becoming ill, the mothers body produces a precise prescription of antibodies for the specific infection the baby is battling, which are passed back to them through the milk. 

‘Hormone’ comes from the greek meaning ‘setting in motion’. Hormones are signalling molecules which trigger action by certain cells in the body. They are stimulated by emotions but also stimulate emotions themselves (for example cortisol or oxytocin). Human milk features an impressive array of different hormones including; endorphins which act as a painkiller, leptin which controls appetite and regulates weight gain, and Epidermal Growth Factor which promotes cell growth. Throughout the day, milk evolves in step with the circadian rhythms. During the nighttime hours, it contains melatonin to promote sleep and teach babies the difference between night and day. Lactation also suppresses the nervous system’s hormonal response to stress so the lactating person is hormonally altered, often becoming a softer, slower and sleepier version of themselves.

Milk is a living and active tissue passed between entities. Evolution dictates the properties of each species’ milk and the type of milk an infant drinks reinforces what kind of animal it will become: Cow’s milk is high in protein because the calf needs to grow quickly to keep up with his mother in the field. Whale milk is thick and fatty like melted cheese because the baby whale needs to develop blubber fast to keep warm. Human milk is watery and low in protein and fat but has a huge number of complex, long-chain fatty acids so that a baby’s brain can develop quickly. 

Milking machines for cows and people are also remarkably similar. The pumps are shaped like a cushioned funnel with a hand lever (electric versions also available) to create suction, which vacuums out the milk.

For humans it helps to look at baby pictures or videos while pumping to stimulate oxytocin and milk ‘let down’. Like looking at porn in a sperm bank, the relatively modern cerebral brain tries to trigger the prehistoric hypothalamus. 

It is estimated that humans were first able to digest milk from cows around 4500 B.C. This was probably initially a desperate way to avoid starvation by early European farmers. Humans would have been lactose intolerant until around 5000 B.C, when a genetic mutation called ‘lactase persistence’ allowed a majority of our species to digest milk after infancy. Prior to that humans certainly drank milk but probably did so while suffering through the symptoms of lactose intolerance.

After the development of this enzyme, the subsequent impact of dairy farming on human history is incalculable. It has shaped us in ways that range from the economic to the microbial. The first vaccine (the word itself comes from the Latin for cow Vaccinus) was developed through dairy farming; doctor’s apprentice Edward Jenner realised that dairy farmers did not contract smallpox and concluded that this was due to their exposure to cowpox – a milder variant of smallpox. Following this doctors began to collect pus from the scabs of cows with cowpox and used this to make a vaccine. 

Pump & Dump; Toxic Maternal

Milk articulates the material world through bodies; bodies that filter and conduct that which goes around, on, and in, them. Bodies eat, drink, absorb and inhale; gathering substances like reservoirs, expelling or concentrating them. When alcohol distilleries expanded in the 19th century they had an excessive amount of swill (a spent-grain waste product of alcohol production). Many therefore opened dairies to feed their cows with this spent-grain. The swill was low in nutrients however, which resulted in poor milk quality and sickness in the cows and whoever drank their milk.

The phrase ‘Toxic Maternal’ is used to refer to lactating humans, whose milk contains poison as well as nourishment (Nelson 2015: 124). The average sample of human breast milk now contains a range of poisons ingested from the lactating person’s environment including paint thinners, dry cleaning fluid, rocket fuel, toilet deodorisers and flame retardants. (Neimanis 2012: 109) The infant drinks these substances along with a blend of hormones, bacteria, vitamins and white blood cells. Milk reminds us we are only as clean as – in fact, constituted by – our surroundings. As Eula Biss puts it in On Immunity:

‘If we do not yet know exactly what the presence of a vast range of chemicals in umbilical cord blood and breast milk might mean for the future of our children’s health, we do at least know that we are no cleaner, even at birth, than our environment at large. We are all already polluted. We have more micro-organisms in our guts than we have cells in our bodies—we are crawling with bacteria and we are full of chemicals. We are, in other words, continuous with everything here on earth. Including, and especially, each other.’ (Biss 2014, 75–76)

Milk Kinship and Milking Kin

Wet nursing is breastfeeding a baby other your own. It is a practice that has likely existed as long as humans have had babies. Wet nurses were hired by higher-class families to breastfeed their infants if the baby’s mother was unable or unwilling to do so herself. Wet nursing occurred in cultures spanning every continent and going as far back as at least ancient Rome (Pedrucci, 2017). Within capitalist, colonialist structures of extreme inequality wet nursing often implied violence, trading one baby off for another: British colonists brought the practice of wet nursing with them to North America, where enslaved women were forced to feed their master’s babies before their own. Similarly, in Europe many lower class wet nurses were forced to abandon their own children in order to work as a wet nurse for another family. (Pedrucci, 2017)

Cross-nursing or breastfeeding a baby other than your own can also be practiced for spiritual reasons. The sacred nature of milk is expressed in the notion of ‘milk kinship’; the bond formed when a baby drinks milk from someone other than a biological relative, in Native American and Islamic cultures. Milk kinship was used as a profound way to connect communities through a material bond, and established a ‘second family’ who would care for an infant if something happened to its biological parents.

In Islam, co-nursed babies, known as ‘milk siblings’ are forbidden from marrying one another on the grounds of incest, as if they are genetically related. Aside from custom this perhaps has some scientific foundation; recently it has been discovered that human milk contains stem cells, undifferentiated cells which can both proliferate indefinitely and develop into any cell in the body, the only other places these cells are found is in embryos, amniotic fluid, bone marrow, sperm and blood. When multiple babies are breastfed by the same person regularly they may share epigenotypes.“If these epigenetic changes can be inherited by the next generations, marriages between individuals breastfed by the same mother may result in the same consequences as consanguineous marriages”. (Karadag et al 2015: 188–196)

Human infants being wet-nursed by a creature of another species is a recurrent theme in classical mythology. Romulus (the founder of Rome) and his twin Remus were raised by a she-wolf, the twins are depicted nursing from her. Telephus, son of the demigod Heracles, was suckled by a deer while Cyrus of Persia was said to have been suckled by a dog. 

These stories were mirrored in real histories. During the 18th and 19th centuries wet nursing was risky due to the proliferation of congenital syphilis, which could pass through milk to the baby or from the baby’s saliva through the nipple. Subsequently many people opted to feed their infants from a goat rather than risk a potentially syphilitic wet nurse. In the 17th and 18th centuries goats or donkeys were used to feed Foundlings within orphanages, each infant was paired with a goat who would come to know them. (Pedrucci, 2017)

It was widely believed that characteristics could pass through milk to nursing infants. For this reason, when the option was available, donkeys were preferred over goats as they were seen to be less ‘libidinous’ in nature. During the 19th century in France a law was proposed to ban disreputable mothers from nursing their own children so that their immoral traits would not be transmitted via the milk (Radbill 1976, p. 22). This transmission was also believed to occur across species; when Peter The Wild Boy was found in northern Germany in 1724 his coarse, curly hair was attributed to his being (supposedly) suckled by a bear, ‘based on the premise that characteristics of the animal foster mother had been transmitted to him via her milk’. (Schiebinger 1993:56)

Until relatively recently, irrespective of the animal from which it came, milk was consumed directly from the teat because this reduced exposure to bacteria. Babies in orphanages would be held underneath goats udders or would lie in cribs on the floor so the goats could stand over them to let them suckle. ( Valenze 2011:159)

When stressed the human body produces cortisol and ceases to lactate. This has to do with early evolution of humans – if a wild animal or other danger was threatening us then the body tells us not to nurse but run. In contrast, cute, baby creatures, even of other species (like puppies) stimulate the production of oxytocin in the body and the breasts leak milk in enthusiasm.

Interspecies suckling was, and continues to be, also practiced the other way around. In Europe and the U.S up until the mid-19th century women were advised to suckle puppies to prepare their nipples for breastfeeding or to drain blocked milk ducts (Radbill 1976: 26). If a mother with a small baby contracted smallpox she could be quarantined with a puppy to breastfeed in order to maintain her milk supply while she recovered. And Saint Veronica Giuliani, an Italian nun and mystic, would allegedly take a lamb to bed with her and nurse it as a symbol of the Lamb of God. (Schiebinger 1993:56)

In many places, humans suckling animals continues to be practiced out of necessity, when animals are relied upon directly for human survival. Famously* women in Turkana, North West Kenya, breastfeed young goats in order to let the animals survive during a drought. *Images of this caused major problems for Facebook’s censorship policy which had a no-nipple policy with the exception of breastfeeding but did not previously include any clause against breastfeeding animals.

Sharing milk, this direct intimacy with other species, is reciprocal and anything but sterile. The practice undermines human exceptionalism, reminding us that we are one of many warm blooded mammals with vulnerable young.

Even in its molecular constitution milk is a polyvalent substance that reaches across the boundaries of species. Breast milk, for instance, contains around 150 oligosaccharides, complex chains of sugars unique to human milk. These molecules can’t be digested by infants; they exist purely to feed and encourage the microbes that populate an infant’s digestive system. In this way milk is both food, and contains the tools for its own digestion.

Philosopher Michael Hardt states that love is destroyed as a political concept by being trapped within identity – love of the same. He argues that for love to be transformative it must be radically open to the unfamiliar and unknown. Heterogenous love for our familiars is ‘eros’ love ascending up to god, in contrast ‘agape’ is a descending and terrestrial love for earthly things. Following Hardt’s definition interspecies suckling could be an expression of agape; a terrestrial, radical and potentially transformative practice which reached a marked end with the advent of pasteurisation.

On the Pasteurisation of Other

Named after Louis Pasteur, Pasteurisation (as a process) changed the ways the relation between self and other were conceptualised (Tsing, 2012: 10). With the discovery of invisible, microscopic enemies everywhere, boundaries between the ‘clean’ and ‘unclean’, the ‘inside’ and ‘outside’ and the ‘self’ and ‘other’ became paramount. Relationships between capitalist expansion and recently discovered ‘colonies’ of bacteria were more than semantic as Anna Tsing articulates, via Bruno Latour:

“…the main problem for showing the importance of Pasteurian germ theory was the necessity of creating laboratory-like hygienic conditions in which people and their domesticates could be kept away from the generally ubiquitous environment of disease microorganisms. Latour suggests that colonial armies in the tropics—where disease ran rampant, limiting colonial conquest—were the first living laboratories for Pasteurian medicine.” (Tsing, 2012: 10)

To undergo pasteurisation, a lot of milk is gathered together and mixed, strained and then heated several times in order to kill bacteria. Following pasteurisation milk becomes a predictable and homogenised product that can be stored, equalised and distributed. As a substance it is also no longer from ‘this cow’ but more generically ‘from cows’ and served from a bottle. Milk as a substance and ontological category enter into an anonymous commons, those who consume it are probably unaware of who produced it. Pasteurisation allows for milk to enter more fully into a capitalist economy. Within this new framework milk flows in one direction: from animal to human, from the rural farm to the increasingly densely populated urban area, from the producer to the consumer.

Following a parallel framework, human milk banks offer ways to donate, collect and share breast milk with those who need it or may struggle to produce it. They operate across Europe, the U.S, the African continent and are slowly spreading across the rest of the world with the notable exception (thus far) of the Islamic world. For Muslims, milk banks challenge beliefs about the intimacy of milk kinship (Karadag et al. p188-196). Interestingly, however, much of the epigenetic science which supports the notions of milk kinship is eradicated by the processes applied to human milk in milk banks. The milk is sorted into age groups (colostrum and mature milk) and then mixed together into large vats before being pasteurised (heated for 30 minutes at 63°c).

Pasteurisation of breast milk kills potentially lethal viruses and diseases which could be passed to infants. It is the process of pasteurisation, therefore, which make milk banks safe and feasible. After pasteurisation it is still considered healthier to give an infant breast milk than formula, but by separating the milk from the producer it is no longer liquid communication. Along with potential pathogens, its microbial composition and bacterial population have also been somewhat eliminated which has significant implications for the baby’s intestinal and immune health. 

Milk Philosophy

Saint Agatha freely offers to a stranger that which is most precious and vital. In (the least violent) depictions of her she carries her tray of clean and blood-free breasts proudly.

In offering her severed breast Agatha presents an image of nursing a stranger, she asks us to give generously and believe there will be enough for all. Luckily milk itself articulates a state of abundance; the mammary glands produce as much as is required to meet demand.

To say milk is food is an obscene oversimplification, it is a deeply programmed, multifaceted nourishing experience which provides everything an infant mammal needs to grow and feel soothed; food, warmth, familiar smell, hormones that calm, ease pain and encourage sleep.

Most of all milk offers a manifest way to relate to the world around us; polluted, intimate, communicative, entangled, complex, nourishing; milk displays that we are constituted by, and inseparable from, our environment and one another. In milk, the ‘immaterial’ such as an emotion becomes the ‘material’, such as food and troubles these categorisations.

In its creamy opacity milk invites us to trust the other, without knowing and to accept molecular contingency. Finally, as living tissue that conducts both microbes and chemicals in the environment, it complicates the perceived boundaries of the body, through it we can understand that ‘health’ is not a private question but a shared state that flows around and between us. 

Key references & further reading:

Biss, Eula, 2014. On Immunity; An Innoculation. Minnesota, Graywolf Press.

Corbin, Alain. 1986. The Foul and The Fragrant – Odor and the French Social Imaginary. Cambridge Massachusettes, Harvard University Press.

Cregan MD, Fan Y, Appelbee A, Brown ML, Klopcic B, Koppen J, Mitoulas LR, Piper KM, Choolani MA, Chong YS, Hartmann 2007. Identification of nestin-positive putative mammary stem cells in human breastmilk. Epub.

Hardt, Michael. 2012. The Procedures of Love No. 068 of 100 Notes – 100 Thoughts produced by documenta(13) Ostfildern Germany Hatje Cantz.

Karadag Ahmet et al. 2015. Human milk banking and milk kinship: Perspectives of mothers in a Muslim country. Journal of Tropical Pediatrics, Volume 61, Issue 3, June 2015, Pages 188–196, https://doi.org/10.1093/tropej/fmv018

Neimanis, Astrida. 2012 “Hydrofeminism: Or, On Becoming a Body of Water.” in Undutiful Daughters: Mobilizing Future Concepts, Bodies and Subjectivities in Feminist Thought and Practice New York: Palgrave Macmillan. 

Nelson, Maggie. 2015. The Argonauts. London, Melville House.

Pedrucci, Giulia. 2017. Mothers for Sale: The case of the Wet Nurse in the Ancient Greek and Roman World. (Academic Paper) Bologna, University of Bologna.

Radbill, Samuel X. 1976. “The Role of Animals in Infant Feeding”. In Hand, Wayland D (ed.). American Folk Medicine: A Symposium. University of California Press.

Schiebinger, Londa L. 1993. Nature’s Body: Gender In The Making Of Modern Science. Rutgers University Press.

Shotwell, Alexis. Complexity and Complicity; An introduction to Constitutive Impurity. Chapter 1 In Against Purity: Living Ethically in Compromised Times. Minneapolis: University of Minnesota Press, 2016.

Tsing, Anna. 2012. Unruly Edges: Mushrooms as Companion Species: For Donna Haraway. North Carolina Duke University Press.

Valenze, Deborah. 2011. Milk: A Local and Global History. Conneticut, Yale University Press.

West, E. and Knight, R. J. 2017. Mothers’ milk: slavery, wet nursing, and black and white women in the Antebellum South. Journal of Southern History, 83 (1). pp. 37­68. Available at http://centaur.reading.ac.uk/66788/

Alonso Cano, Miraculous Lactation of Saint Bernard, 1650. Source.

Alonso Cano, Miraculous Lactation of Saint Bernard, 1650. Source.

Kari Robertson

Kari Robertson (b.1988 Edinburgh, UK) is a visual artist, teacher and researcher largely concerned with eco-social themes.

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