Soothing Weak Nerves: Tropical Anxieties, Missionary Guidance and Moral Hygiene

Abstract

This chapter argues that the contemporary image of the tropics as a site of jeopardy and trial offered an effective framework to preach the Basel Mission’s pious code of conduct to a broader audience. The personal regimen recommended in the medical literature on tropical hygiene around 1900 focussed on asceticism, self-discipline and temperance. These measures were congruent with the proscriptions of Pietist purity, underlining the continued belief in a connection between morality and disease. This puritan dimension of tropical hygiene allowed the Basel medical missionaries to position themselves as experts on the matter and mould scientific and colonial debates with their religious logic. They enjoyed extensive moral authority among the colonial public, not only advising how the sick should be treated but also prescribing healthy diets, behaviours and lifestyles. Although many of the debates surrounding tropical hygiene were carried out in medical journals and other specialised publications, their influence ranged far beyond the disciplinary boundaries of tropical medicine, gaining currency in wider social and political contexts.

Tropical hygiene was a concept with deeper and wider meaning than later usage of the word “hygiene” would suggest. It evoked a spiritual, ascetic ideal of purity and self-control, a quality that conquered the dangers of a hostile physical and social environment through the mastery of mind over body. This puritan dimension of tropical hygiene allowed the Basel medical missionaries to position themselves as experts on the matter and mould scientific and colonial debates with their religious logic. They enjoyed extensive moral authority among the colonial public, not only advising how the sick should be treated but also prescribing healthy diets, behaviours and lifestyles. Although many of the debates surrounding tropical hygiene were carried out in medical journals and other specialised publications, their influence ranged far beyond the disciplinary boundaries of tropical medicine, gaining currency in wider social and political contexts.

1 Resurging Climatic Fears

Advice on tropical hygiene and the treatment of tropical diseases had only played a minor role in travel guidebooks in the first half of the nineteenth century.¹ One of the first handbooks dealing with such questions explicitly with regard to Africa was authored by James Africanus Beale Horton.² Born as a son of a former slave in Sierra Leone in 1835, he was one of the first Africans to train as a physician at a British university in the nineteenth century. He served as a doctor in the West India Regiment on the Gold Coast in 1860 and published his medical compendium advising Europeans on how to stay in good health in the tropics in 1867.³ Horton asserted that the tropical climate and the unfamiliar environment posed a great threat to the physical and mental health of Europeans. “Maladies peculiar to tropical climates,” he argued, “have the most mischievous effect in checking the progress of true civilisation.”⁴

Despite a considerable decline in death rates among Europeans in West Africa from 1875, optimism regarding the adaptability of Europeans to the tropics gradually vanished.⁵ The late nineteenth century saw a resurgence of climatic fears as theories became charged with new and sophisticated explanatory models. The notion that climate and physiology affected one’s resistance to illness was in many ways inconsistent with the teachings of germ theory and the new understanding of parasitology. Experts in the field of tropical medicine now argued, however, that even if the tropical climate did not actually cause disease, it had grievous effects on the constitution of Europeans and predisposed them to contagion.⁶ Individual hygiene and the internalisation of a catalogue of appropriate measures were thus regarded as essential for survival, and discipline took on an important role in the understanding of suitability for the tropics.

Patrick Manson delivered an address on Tropical Research in its Relation to the Missionary Enterprise at Livingstone College in 1908, which the Society for Medical Mission in Stuttgart translated and published in German in 1909. He opened his lecture by recalling that “thirty years ago no man knew what Malaria was; no man had the slightest conception of how it was caused, how it was transmitted, nor what was the nature of the germ.”⁷ He proceeded by enumerating a number of disease pathogens that had been identified and could now be curbed by medical science. “One important deduction from this modern knowledge”, he concluded was “that Tropical diseases are not produced, as formerly supposed, by climate.” Instead, disease depended “upon the intermediaries through which the germ cause of the disease is transmitted and these intermediaries are prevalent in the Tropics.”⁸

Manson’s statement illustrates that while the discovery of the pathogens involved in diseases such as malaria, cholera, plague or typhoid and the gradual development of vaccines brought new hope to medical research in tropical colonies, it also complicated the understanding of diseases there. The tropical environment, which for much of the nineteenth century appeared to Europeans to be full of noxious, foul air, henceforth seemed to be infested with invisible germs.⁹ By 1900, the tropics and tropical bodies were seen as the natural home of deadly pathogens, which scientists thought to combat with the help of germ theory and laboratory medicine.¹⁰

Medical and travel guides for tropical territories around 1900 were replete with warnings about the climate and advice on preventive measures, collectively referred to as tropical hygiene.¹¹ Michael Pesek has characterised these publications as “mobile education institutions” that tried to transfer the ideal of the laboratory onto the field.¹² As knowledge on tropical diseases grew, medical scientists formulated ever more detailed guidelines of behaviour, lifestyle and equipment. The discovery of the transmission paths of malaria, for instance, led to new recommendations on protective clothing and nets, means of transport and construction away from mosquito breeding sites. The Basel Mission doctors’ advice on house building in West Africa according to the newest hygiene standards aroused considerable interest in the contemporary colonial press.¹³

The physician Alexander Lion, who served as medical officer in German South-West Africa between 1904 and 1906, published a book with advice on tropical hygiene in 1907 that found wide recognition and was also part of the Basel Mission library. He stated that a “reasonable lifestyle protects against tropical diseases or reduces their danger.” Therefore, he instructed: “Do not drink too much, never get drunk, ideally practise sexual abstinence, take daily baths and do not get angry.”¹⁴ The personal regimen recommended in the medical literature focussed on asceticism, self-discipline and temperance. These measures were congruent with the proscriptions of Pietist purity, underlining the continued belief in a connection between morality and disease.¹⁵

The question of whether Europeans could cope with the health and moral challenges posed by the tropical climate was a key aspect of virtually every debate about the viability of the colonial project between 1885 and 1914. It had this larger resonance because, on the one hand, it spoke to the deep-felt anxieties of Europeans residing in tropical colonies. For them, advice on tropical hygiene possessed an immediacy that derived from personal worries about maintaining health and sanity in an alien climate. It gave scientifically legitimised meaning to their experience and prescribed a specific code of conduct, allowing them to define and assert their cultural and racial identities in contrast to the people native to the colonies. What tropical hygiene offered was an “oddly satisfying diagnosis of these concerns, at once prescriptive and proscriptive in its recommendations,” as Dane Kennedy argued.¹⁶

On the other hand, tropical hygiene addressed broader concerns of imperial policy-makers about the very shape and future of European colonialism. Metropolitan authorities looked at tropical colonies as potential homelands in reaction to fears of overpopulation in Europe. However, at the same time, the future of these recently acquired possessions in Africa and elsewhere raised crucial issues about the role and position of white men and women in that future, revealing fundamental political uncertainties.¹⁷ They implemented a rigorous and highly restrictive selection process to ensure that only able-bodied and mentally stable Europeans relocated to the colonies. Potential emigrants, military recruits and administrative personnel had to undergo regular medical check-ups and preparatory measures to assess whether they were suited for life in a tropical colony or not.¹⁸

Europeans’ colonial experience was substantially shaped by negative emotions such as anxiety, insecurity and fear, as recent studies have emphasised.¹⁹ The debate on the difficulty for Europeans to acclimatise in tropical colonies subtly called into question European supremacy, exposing the colonial situation as an experience of permanent scientific and political crisis as well as imperial helplessness. New theories of race emerging in the late nineteenth century increasingly drew upon evolutionary arguments and implied that European bodies were unfit for African conditions.²⁰ Tropical hygiene consequently was an enduring concern of colonial rule and an essential aspect of imperial expansion. Instead of reducing climatic fears, most scientific discoveries in the late nineteenth and early twentieth centuries triggered the development of deeper tropical anxieties, with a new vocabulary through which they could be expressed.

2 Missionary Advice on Moral Hygiene

The contemporary image of the tropics as a site of jeopardy and trial offered an effective framework to preach the Basel Mission’s Pietist code of conduct to a broader audience. The evangelical struggle against filth, alcoholism and sexual immorality at home gained significance abroad due to the tropical setting, which was commonly conceived of as a perilous place for Europeans. Tropical colonies exerted moral pressure on potential immigrants by magnifying the serious repercussions of ignoring hygiene guidelines. They demanded a regime of moral hygiene every bit as rigorous as physical hygiene measures. All guidebooks on tropical hygiene appearing after 1900 saw mental strength and emotional resilience as an imperative prerequisite for Europeans who planned on staying in the tropics. Already in 1891, Fisch had made clear in the foreword of Tropische Krankheiten that the tropics were only feasible for the scientifically enlightened and morally disciplined:

The main purpose of the manual is to initiate a rational treatment of malaria and, besides the various advice on the prevention and treatment of diseases, to demonstrate that the surrender of many Europeans to debauchery poses a grave danger to their lives. […] May the booklet fulfil its purpose and thus encourage the true civilisation, i.e. Christianisation of the Dark Continent.²¹

Fisch intertwined scientific and sermonic modes of speech to warn his readers of the serious consequences of moral misconduct. He cautioned how much a lack of self-discipline was a risk to the civilising project in Africa and left no doubt that progress could only be achieved by the spread of Christian values and behaviour. By combining moral purity with physical discipline, his book not only offered practical advice for survival in the tropics but also depicted the individual European as an agent of imperial, rational and, above all, Christian Europe. Fisch turned the medical and colonial discourse on tropical hygiene into a religious responsibility by emphasising that “true civilisation” meant Christian civilisation. In order to advance this civilising mission, Europeans had to comply with detailed rules of personal hygiene, not only to preserve their own health but also to uplift the population in the colonies.

The medical discourse on Africa shows that environmental, social and cultural lines of explanation continued to dominate scientific knowledge.²² From 1913, the influential magazine Koloniale Rundschau, published by the German Colonial Society, included a specialised quarterly dedicated to tropical hygiene, the Tropenhygienische Rundschau, edited by Gottlieb Olpp, the director of the Institute for Medical Mission in Tubingen. Reports published in the Tropenhygienische Rundschau compared figures released by state institutions, such as the medical services, with statistics issued by mission societies. They frequently underscored the point that the latter promised a lower infant mortality rate, a higher life expectancy for Africans and Europeans, and overall improved the practice of hygiene.²³ Mission medicine, which was aimed at treating body, mind and soul, offered a holistic approach in dealing with the health and moral challenges posed by life in tropical colonies.

The familiarity of the Basel medical missionaries with tropical climates ensured that their wide-ranging studies on tropical hygiene captured the attention of a general public concerned with the colonial question. They offered extensive advice on anatomy and physiology, air and ventilation, water and sanitation, house and school building, drainage and plumbing, gear and means of transport, diet and cooking, washing and personal cleanliness, maternal and child health, social and work life, sleep patterns and physical activity, and diseases and their prevention. Such a list indicates the degree to which hygiene was thought to have a potentially revolutionary impact on all aspects of personal and public life. Their articles appeared in the Deutsche Kolonialzeitung, in a range of missionary magazines, in the Archiv- für Schiffs- und Tropenhygiene and in other medical publications.²⁴

Tropical hygiene enjoyed considerable influence among Europeans in the colonies and metropolitan interest groups because it spoke the language of medical science and carried the authority of doctors’ expertise. At the same time, the tropics constituted a moral arena, a risky space in which circumspection and self-control were as essential to survival as physical vigour and medication.²⁵ The Basel Mission doctors used their credibility in the field of tropical hygiene to promote their Pietist beliefs beyond evangelical circles. Their hygiene guidelines did not simply comprise measures to maintain health but actively sought to establish new behavioural norms in line with their purity ideals. In this sense, hygiene was not merely the absence of illness but a positive power to control oneself and one’s environment. The popularity of their articles and handbooks on tropical hygiene indicates that hygienic knowledge around 1900 was infused with pious notions of purity.²⁶

Most scientists, missionaries and colonialists agreed that hygiene in Africa was first and foremost a question of upholding discipline in the absence of the habitual societal pressures and amenities of civilisation. Such discipline was all the more important because self-control was generally believed to be a precondition for the control of others.²⁷ Hey clearly stated that “the biggest difficulty in the education of subordinates” lay in “the ill-breeding of the Europeans themselves,” since people who were not “properly educated themselves” could “obviously not educate others.” He emphasised that “the correct influence of Europeans and particularly of every individual must help to lay the foundation on which a fruitful colonial policy can be built.”²⁸ From this point of view, the greatest threat to the success of the colonial project lay in the moral integrity of the people assigned to carry out colonial rule.

Two topics in particular highlight that tropical hygiene played into the Basel Mission doctors’ hands: alcohol consumption and sexual transgression. As early as 1894, at the International Congress for Hygiene and Demography in Budapest, British surgeon general Charles Richard Francis warned Europeans against the intake of alcohol in tropical countries.²⁹ In the following years, many German experts in tropical medicine concurred with this advice.³⁰ Drinking habits were seen as a major impediment to the colonial project in West Africa, not only damaging the health of Europeans but also “the reputation of the white race.”³¹ It was believed that the misuse of alcohol provoked moral transgressions, thereby undermining the civilising mission amongst the African population. The Basel missionaries, and alcohol abstainers more generally, appreciated this line of argument because it supported their agenda.³²

Rudolf Fisch addressed the “moral behaviour of Europeans in the tropics” explicitly in a chapter of Tropische Krankheiten, describing it as “a blot that clings to the Christian name and impedes the true civilisation of the Black Continent.”³³ His main concern was the promiscuity of white men in West Africa, which in his view inevitably led to death or a forced journey home. Once home, Fisch warned, these “corrupt people without true honour” would have to deal with “the stigma on their conscience” and a “shattered body as the punishment of disdainful pleasure, which the righteous God allots to them.”³⁴ Along with scientific arguments and carefully reviewed medical findings, Fisch’s Tropische Krankheiten conveyed the idea that “fornication” posed as much of a risk to the health of Europeans as malaria or black water fever. From his perspective, diseases caused by alcohol indulgence and sexual promiscuity were the visible manifestations of both religious sin and social deviance.

3 Weak Nerves and Missionary Resilience

Rudolf Fisch drafted a manuscript entitled “How do I make myself suitable for service in the tropics?” for the students at the Basel Mission seminary. He reminded them that “the missionary profession” posed “manifold challenges to body and soul,” unmatched by any other profession.³⁵ The tropical climate demanded a “considerable measure of energy,” which Fisch defined as a “capacity of the soul.” He concluded: “Anyone who wants to prepare for service in the tropics with prospects of success must be free from any physical ailments and especially free from pathological mental dispossessions.”³⁶ The latter included what Fisch called “hysteria” and “neurasthenia,” a term coined by the American neurologist George M. Beard in the 1870s. Neurasthenia was described as a form of nervous exhaustion induced by the pressures of modern civilisation and developed into a widespread diagnosis in Europe and America.³⁷

The late nineteenth century saw the identification of tropical neurasthenia, which according to some sources existed in near epidemic proportions among Europeans abroad. On the Gold Coast, the number of colonial officials sent home as medical invalids based on the diagnosis of tropical neurasthenia was nearly on a par with malaria.³⁸ Like its metropolitan namesake, tropical neurasthenia was viewed to be a form of nerve damage or exhaustion, presenting many similar symptoms.³⁹ Unlike neurasthenia at home, however, it was not considered to be caused by the burdens of modern civilisation.⁴⁰ Au contraire, the root of tropical neurasthenia was seen to lie in the combined effect of the tropical climate, physical exertion and mental strain in the face of seclusion from modern society, which corrupted the nervous system of the white male body.⁴¹

By relocating the diagnosis of neurasthenia to colonial contexts, physicians applied the authority of medical knowledge to a disorder that had been described by Europeans in the tropics for decades as “tropical inertia,” “tropical amnesia,” “Punjab head,” “Burmah head” or “Tropenkoller” in German-speaking circles.⁴² In his 1906 publication, the colonial doctor Ludwig Külz recalled a feverish episode in northern Togo, where he almost shot his African companions suspecting them of projecting arrows at him after hearing a number of noises. In retrospect, he considered his irrational behaviour a typical example of the neurological condition many white men developed in the tropics, Tropenkoller.⁴³

Both adversaries and advocates of colonialism used the condition to describe a dramatic loss of self-control, suffered by white men in the tropics, causing them to transgress sexual boundaries and exert excessive violence.⁴⁴ Early warning signs included indolence, lack of initiative, a drift into alcoholism and a disregard for the rules of personal hygiene and moral conduct. Most medical and psychiatric experts agreed that tropical neurasthenia occurred most often where the “cultural straitjacket” was loosened and, in contrast to the situation in the motherland, neither the “watchful eye of the law and the general public” nor the customs and conventions of civilisation restricted the individual’s conduct.⁴⁵ Thus an explosive combination of lack of restraint and an inclination to violence materialised, which erupted in inconsiderate and cruel behaviour that contradicted “common moral and juridical opinion.”⁴⁶

Fisch elaborated on neurasthenia in his manuscript on suitability for service in the tropics, arguing that tropical neurasthenia was not a distinct condition to the one found in Europe. While he admitted that the tropical world certainly posed greater challenges to Europeans in both physical and moral terms than more temperate regions, neurasthenia was ultimately a mental condition originating from a lack of modesty and a failure of mastery of mind over body. According to him, the condition known as Nervenschwäche—weakness of the nerves—in German medical literature bore the wrong name, since “it is not the nerves but the part of consciousness that we call the soul which is altered by the disease.”⁴⁷

Fisch characterised neurasthenia as a form of egocentrism or narcissism that resulted from a lack of Christian asceticism, devotion and sacrifice. He believed that “almost all of us suffer from this condition” in which “the I has taken centre stage of thinking, wanting and feeling.”⁴⁸ Therefore, if prospective missionaries wished to serve in the tropics, they had “to recognise their enemy” and resolutely oppose it from the beginning.⁴⁹ The only way to avoid neurasthenia in Fisch’s view was “to practise selfless love,” “to devotedly live for others and serve them.”⁵⁰ He concluded that no disease was “as incompatible with powerful, pneumatic Christianity as neurasthenia.”⁵¹

Like Fisch, a number of tropical doctors refused to accept Tropenkoller as a medical diagnosis, arguing that while moving from a temperate into a tropical climate certainly contributed to nervous irritability, people with weak nerves tended to behave impulsively in all climatic zones. Heinrich Botho Scheube, the author of a medical textbook on “diseases in warm countries,” firmly rejected tropical frenzy, calling it a “political disease.”⁵² The tropical physician Carl Mense held that the tropical climate, boredom, loneliness and disappointment of not finding “oriental opulence and paradisiacal freedom” could indeed cause neurasthenia. Nonetheless, he refused to accept that nervous disturbance was an inevitable side effect of colonial service because some men “learned to love tropical nature” and enjoyed the recreation of nature study and collecting while others even found the privations of colonial life conducive to mental health.⁵³

Friedrich Hey’s Tropenarzt included a chapter on “Tropenkoller und Geisteskrankheiten”—tropical frenzy and mental illnesses.⁵⁴ He explained that the title merely reflected an established expression and not his view, clarifying that “there are no mental diseases.” He elaborated on his statement by arguing that “the mind can never fall ill but it can certainly be clouded and hindered in its actions when a person has weak nerves or a weak brain.”⁵⁵ According to Hey, tropical influences were not the actual root cause of the widespread diagnosis of Tropenkoller: “It is mostly, or we may safely say always, people who already at home get irritated easily and suffer from neurasthenia.”⁵⁶ Once in the tropics, however, the condition was exacerbated due to the “harmful influence of the tropical climate on the central nervous system,” malaria infections, alcohol abuse and “unedifying cases of mental depressions” caused by “detrimental social interactions.”⁵⁷

The German pastor Philipp Horbach picked up on the controversy surrounding tropical neurasthenia in 1904 by asking: “If the climate has an influence on such excesses, why do they not occur among missionaries who live in the same climate as their fellow European countrymen?”⁵⁸ Horbach’s rhetorical question highlights that missionaries were commonly regarded as less susceptible to tropical neurasthenia than other Europeans, although a pre-First World War study of 1479 stricken British missionaries found that “nervous conditions of a neurasthenic type” were the largest single cause of medical repatriation, accounting for 20.8 per cent from Africa.⁵⁹ Nonetheless, missionaries appeared to be better prepared for the physical and mental challenges that awaited them abroad than most military and colonial personnel.

A look at the external influences that were considered to cause or aggravate nervous conditions explains why the Basel missionaries might have been less likely to be diagnosed with tropical neurasthenia than other groups of Europeans: they included alcohol indulgence, overemphasis of material goods, deprivation of familiar conviviality and comfortable consumer goods, physical and mental adjustment problems, morphine abuse and sexual excesses.⁶⁰ The Basel Mission’s behavioural norms represented the polar opposite of these trigger factors by emphasising the importance of temperance, spirituality, a strong community bond, asceticism, intensive preparation, sobriety and Christian marriage. “Missionary service” was a “school of self-renunciation” as Fisch put it.⁶¹

The Basel Mission did everything in their power to prevent being associated with cases of tropical neurasthenia. By the time the Basel missionaries arrived in the tropics, they had acquired a great deal of experience in discipline, asceticism and self-control under the supervision of their instructors and fellow students in Basel. The Basel Mission’s official regulations laid down that it was “a duty to God, who bestows life and health, to do what is necessary to maintain these gifts.” The Committee expected every missionary to “conscientiously observe the rules for the protection and conservation of his health, gained from experience and science” as “proof of his diligence and faith to his calling.” They cautioned that “the reckless and stubborn disregard of these rules” would be seen “as a sign of the lack of the right spirit of obedience and humility, of simplicity and sobriety, which accounts for an essential part of the suitability for missionary service.”⁶²

Eva Bischoff demonstrated that the diagnosis of Tropenkoller, which simultaneously gained currency in public debates, literary representations and judicial practice, “was successful not because it accurately described what had happened in the colonies, but because it enabled historical actors to further their scientific, political, and personal agendas.”⁶³ Rudolf Fisch and Friedrich Hey denied that the tropical climate actually caused neurasthenia but nevertheless cautioned against moral recklessness if one was to avoid falling prey to tropical frenzy. They used the controversial issue to push a distinctly religious agenda in which moral purity and bodily chastity were inextricably linked. Their message gained the approval of colonial enthusiasts, who emphasised that the demographic weakness of European communities in tropical colonies required maintaining behavioural norms and patrolling cultural boundaries.

4 Boundaries of Colonial Rule

The Basel Mission doctors did not differentiate between neurasthenia at home and abroad because, according to them, the condition reflected an individual’s mental disposition and spiritual health, regardless of climatic and environmental factors. They were, nevertheless, heavily engaged in debating neurasthenic cases occurring in the tropics, arguing that it was only through strict discipline of the individual that a complete moral collapse of colonial society could be avoided. They cautioned the colonial public about the dangers of involving mentally unstable or neurasthenic people into the colonial enterprise, as Friedrich Hey’s warning illustrates:

Anyone who tends to have mental breakdowns at home, who is easily irritable or nervous, should not be allowed in the tropics and if it becomes apparent only when in the tropics, he has to be sent home immediately for his own and other people’s sake. For the colonies, only the best is just about good enough. Colonial authorities, trading firms etc. should keep this in mind.⁶⁴

By stressing the importance of self-control in upholding colonial rule, Hey argued that nervous conditions represented not only a lack of self-discipline but a risk to the body politic. Anne Crozier showed that neurasthenic diagnoses were used to confine and deport Europeans seen as weak and irrational for fear that their behaviour would tarnish the image of colonial officials and therefore undermine European claims of cultural and racial superiority.⁶⁵ The concern for the mental disposition of Europeans in the tropics not only preoccupied imperial stakeholders but became a key feature in the popular imagination of the colonial world, raising fundamental questions about the feasibility of the colonial project and the place of Europeans in the world.⁶⁶

White men appeared to be at particular risk of nervous breakdowns because they spent more time on the colonial front lines, making them susceptible to alcoholism, sexual excesses and neurasthenic conditions.⁶⁷ The medical discourse on mental illnesses induced by life in the tropics excused the behaviour of white men in tropical colonies. It relieved them of their accountability, for example in cases where criminals were sent back to the “moderate” European climate instead of being sent to prison. Supporters of colonialism employed the idea that mental disorders were responsible for colonial violence and sexual transgressions to disguise and trivialise the system’s inherently violent nature.⁶⁸

Moreover, the substantial research into mental disorders reassured Europeans in the tropics that their discomfort was taken seriously and therapies were being developed. The neurasthenic cases described in medical and travel guides around 1900 provided scientific explanations for a wide array of symptoms many white men experienced in tropical colonies. Handbooks on tropical hygiene offered them support for their nervous conditions while simultaneously demanding that they exhibit the moral discipline necessary to maintain the stability of the colonial order.⁶⁹

The large number of single men in the colonies constituted an ongoing concern for colonial rule.⁷⁰ Medical and popular debates substantially revolved around sexual issues such as impotence, concupiscence and miscegenation. It was feared that white men would either turn to black women for sexual gratification, thereby fathering mixed-race progeny and eroding racial purity or cultural identity, or give up sex altogether, thereby generating various neuroses and undermining their masculine sense of self.⁷¹ Marriage to European women clearly offered the most suitable solution to this problem but for the majority of white men in the tropics, this was not a viable option. In contrast to the Basel missionaries, their employers or incomes prevented them from bringing their wives to the colonies.⁷²

Fisch called on politicians and directors to increase the wages of colonial administrators and traders so they could afford to bring their European wives to the tropics: “A lot would be gained because a noble woman is a more effective protection against the reckless life around her than anything else, except true fear of God and unfeigned piety.”⁷³ However, for those white women who did take up residence in the tropics, as wives or in other capacities, such as deaconesses, teachers and nurses, the disease environment was thought to be no less threatening.⁷⁴ In addition to contracting the standard array of neurasthenic ills, these women were warned that they would likely suffer from irregular menstrual cycles and frequent miscarriages. Virchow went so far as to pin the future of European communities in the colonies on the health of the female body, formulating the bleak prospect that the tropics would make white women infertile.⁷⁵

Anxieties over racial and gender boundaries were frequently sexualised, particularly on imperial frontiers.⁷⁶ The debates on the sexuality of white men in tropical colonies not only reflected worries for their physical well-being but centred on the importance of maintaining their racial and cultural integrity. The danger of too much acculturation was considered particularly acute if they shared their lives with a non-European concubine or wife, for this put them in peril of adopting an “indigenous” lifestyle; in short, of “going native” or “verkaffern” as it was coined in Germany.⁷⁷ These apprehensions found their clearest expression in the rejection of marriages between colonisers and colonised.⁷⁸

Although the Basel Mission principally opposed miscegenation and cohabitation, interracial marriages constituted a complex subject. The Committee feared that by declaring marriages to African women invalid and banning future marriages, white men would be encouraged to cohabit with black women, fathering their children, without having to take responsibility for their actions. In his 1891 edition of Tropische Krankheiten, Fisch wrote that instead of allowing men to lead a life of debauchery by outlawing interracial marriages, colonial administrations should hold such men accountable and not punish those who acted honourably and lived conjugally with African women.⁷⁹ In West Africa, extramarital relationships between European colonists and African women were part of everyday life while legally binding marriages remained the exception.⁸⁰

Fisch stated that most white men in West Africa behaved “like animals,” paid prostitutes, abandoned the children they fathered abroad and passed on syphilis to their children at home. Ultimately, he saw it as the government’s responsibility to ensure that the children begotten by Europeans in West Africa received support from their fathers and a proper school education.⁸¹ To evangelicals, the promiscuity of large numbers of European men in the tropics was not simply sinful but also smeared the Christian reputation and undercut the progress of the civilising mission.⁸² In 1912, Fisch painted a dark picture of the legacy that European men would leave in tropical colonies, if they did not control their sexual urges: “How horrible it will be, when heathen women will sue Christians one day because instead of bringing them the word of life, which made us civilised, they brought them moral ruin, venereal diseases and decay.”⁸³

Non-marital sexual interactions between a black woman and a white man did not question the existing racial and sexual balance of power, as Philippa Levine has argued.⁸⁴ While they certainly went against contemporary concerns expressed in the field of tropical medicine and hygiene, they actually reinforced the established power dynamics in the colonies: the rule of Europeans over Africans and their bodies.⁸⁵ Interracial marriages and particularly the offspring resulting from these unions, by contrast, posed a danger to the status quo in the colonies by undermining cultural and racial distinctions. A handful of Basel missionaries transgressed these boundaries by marrying African women, the most famous example being that of Johannes Zimmermann marrying Catherine Mulgrave, originally from the West Indies, in 1851. The Committee, however, denied such couples the right to move to Europe with their families.⁸⁶

“Going native” was a highly charged issue since it diluted the idea of European cultural hegemony and racial superiority. Government physicians, colonial authorities and mission boards insisted that if Europeans hoped to retain their health, sanity and cultural identity, they had to restore themselves with occasional visits to cooler, more familiar surroundings.⁸⁷ Albert Plehn emphasised the importance of home leaves not only to retain health but aslo a “national sense of belonging,” urging colonists “to stay acclimatised at home and repeatedly gather fresh powers from home for the victorious battle against the foreign climate abroad.”⁸⁸ The Committee prescribed extended home leaves and regular visits to hill stations during hot and humid months. Hill stations were a central feature of European life in tropical colonies, forming spatial enclaves that symbolised European unity and demarcation from the climatically and culturally alien environment.⁸⁹

On the Gold Coast, the Basel Mission’s sanatorium, located on the hill station in Aburi, accommodated a range of Europeans from different backgrounds, including British administrators, German traders, French explorers and Catholic priests, offering them recreation from the exertions of life in the tropics and a place of exchange.⁹⁰ In Cameroon, the Basel Mission opened a health resort in 1903 at the hill station Buea at Mount Cameroon, where Europeans received medical assistance and were hosted with fresh vegetables, milk, butter and cheese.⁹¹ David N. Livingstone has argued for hill stations in British colonies that “the carving out of such spaces can be seen as symptomatic of a more general Victorian preoccupation with a bi-polar classifying of places into the sickly and the salubrious.”⁹² At the same time, these European sanctuaries highlighted the limits of the European presence in tropical colonies.

The tropical world had its own moral economy, not only threatening Europeans’ physical and mental health but also their cultural heritage. Handbooks on tropical hygiene recommended cultural commodities and spaces such as gramophones, pianos, reading rooms and skittle alleys, in short “a somewhat higher kind of conviviality,” to distract white men from the dangers lurking in the tropics such as alcohol and women.⁹³ Self-control required the control of one’s environment, which above all meant maintaining distance from the country to be ruled and its people. Therefore, experts in the field of tropical hygiene exhorted Europeans to set themselves apart from their environment in the colonies with the help of protective equipment and practices of withdrawal.⁹⁴

Friedrich Plehn recommended a rigorous daily routine, particularly in “an uncivilised environment” where one needed disciplining signals such as the changing of clothes before meals to remind oneself where one came from.⁹⁵ Carl Mense argued that hobbies such as collecting, scientific observations and photography were indispensable to tackle monotony and solitude, and make life in the tropics bearable.⁹⁶ Scientists, administrators and missionaries made the chores of knowledge production, including taking regular observations and measurements, collecting zoological, botanical and geological specimens, acquiring ethnographic objects, drawing maps, gathering information, and keeping logs and diaries, a form of hygiene and often a question of preserving European cultural identity.⁹⁷

The controversial debates about European acclimatisation and acculturation depicted the tropics as a site of a racial struggle for survival.⁹⁸ However, against a backdrop of what were at times catastrophic experiences of illness and mortality suffered by white settlers, missionaries and officers, the biological argument of racial superiority could hardly be sustained.⁹⁹ A purely physical definition of tropical fitness, portraying colonial rule as a consequence of racial supremacy, did not prevail in colonial campaigns. In the end, arguments for the superiority of European civilisation had to take a circuitous route by appealing to cultural values and regulated patterns of behaviour.¹⁰⁰

Handbooks on tropical hygiene prescribed a set of guidelines, which promised to uphold the moral and cultural integrity of Europeans in tropical colonies by combining physical fitness with mental and political self-possession. They were not reflections of commonly shared knowledge but creative sites of a new type of knowledge that tied personal conduct to the success of the colonial project. This was reinforced via the legitimising discourse of medical science. The very precise guidance and advice for tropical hygiene “seemed to have been a psychological necessity,” as Philipp Curtin argued. According to him, “to think that life and death were pure chance beyond human knowledge would have been intolerable,” especially in areas where Europeans suffered high mortality, like in West Africa: “It was much more satisfying to believe the dead had broken one or another of a numerous and complex system of taboos.”¹⁰¹

The history of tropical hygiene shows that anxiety, fear and unease often lurked behind European colonial rule, or as Mark Harrison phrased it, “feelings of superiority and vulnerability were two sides of the same imperial coin.”¹⁰² The Basel Mission doctors argued that the exercise of effective self-control, as a basis for realising the civilising mission, called for religious virtues such as self-examination and asceticism. The self-techniques and renunciation practices engrained in Pietist purity rituals fell onto fertile soil in tropical colonies because these places were construed as a world in extremis, where a high price would be paid for indulgence, carelessness and misconduct. The Basel Mission doctors’ publications on tropical hygiene formed a trusted source of information through which Europeans interpreted their experience in tropical colonies. They provided commentary on the political choices and constraints of imperialism itself.