John Lidwell-Durnin

During the eighteenth century, the discovery of sexual reproduction in insect species prompted the demise of spontaneous generation and new developments in natural history, theology, and political economy. The sexual lives of insects prompted debates on whether insects were governed by desire, free will, and even marital tendency. Fuelled by the democratisation of microscopy, early modern entomology took a new turn and breadth: the study of insects and of their sexual lives provided unexpected new insights into human sexuality, reproduction, and Malthusian fears of overpopulation. This article surveys the intellectual culture of entomology and natural history during the crucial decades when entomologists worked to quantify the reproductive capacities of insect species. Assessing the influences these entomological works had within political economy and theology, we argue that the sexual lives of insects − once analysed and delineated − influenced familiar ideological features of the intellectual landscape of the late Enlightenment, particularly in the theological philosophies of northern Europe and in the political economy of population in Britain.

In the nineteenth century, farmers, doctors, and the wider public shared a family of questions and anxieties concerning heredity. Questions over whether injuries, mutilations, and bad habits could be transmitted to offspring had existed for centuries, but found renewed urgency in the popular and practical scientific press from the 1820s onwards. Sometimes referred to as “Lamarckism” or “the inheritance of acquired characteristics,” the potential for transmitting both desirable and disastrous traits to offspring was one of the most pressing scientific questions of the nineteenth century. As I argue in this paper, Carpenter’s religious commitments to abolition and the temperance movement shaped his understanding of heredity. But this also committed him to a body of evidence for the inheritance of acquired characteristics that was coming under criticism for being untrustworthy. Carpenter used his popular treatises on physiology to promote these older, familiar ideas about heredity because they provided vital means of arguing for the unity of mankind and the hereditary dangers of intemperance. While early nineteenth century physiology has been seen by some historians as a challenge to religious authority, given its potentially materialist accounts of the body and the actions of the soul, this paper demonstrates how the missionary and institutional activities of the Unitarian church were ideologically supported by Carpenter’s publications.

Climate change and the failure of crops are significant but overlooked events in the history of heredity. Bad weather and dangerously low harvests provided momentum and urgency for answers to questions about how best to improve and acclimatize staple varieties. In the 1790s, a series of crop failures in Britain led to the popularization of and widespread debate over Thomas Andrew Knight’s suggestion that poor weather was in fact largely unconnected to the bad harvests. Rather, Knight argued, Britain’s older varieties—particularly its fruit trees—were coming to the natural end of their lifespans. At a period when Britain was trying to maximize its agricultural land usage, Knight campaigned that his fellow farmers ought to set aside land and resources in order to cultivate new varieties—an expensive and time-consuming procedure—in order to avoid disaster. In this paper, I argue that Knight’s lifelong commitment to his position demonstrates the role played by changes in climate and weather on popular understandings of plant heredity. Further, drawing upon the historiography of Britain’s climate and agriculture, I show that despite reliable weather and good harvests, Knight’s campaign survived for several decades before the continued health of Britain’s trees was finally treated as sufficient evidence to dispense with Knight’s warnings. This case provides a means of thinking about the history of heredity as it is shaped and impacted by changes in climate and local conditions.

‘Adam’s laburnum’, produced by accident in 1825 by Jean-Louis Adam, a nurseryman in Vitry, became a commercial success within the plant trade for its striking mix of yellow and purple flowers. After it came to the attention of members of La Société d’Horticulture de Paris, the tree gained enormous fame as a potential instance of the much sought-after ‘graft hybrid’, a hypothetical idea that by grafting one plant onto another, a mixture of the two could be produced. As I show in this paper, many eminent botanists and gardeners, including Charles Darwin, both experimented with Adam’s laburnum and argued over how it might have been produced and what light, if any, it shed on the laws of heredity. Despite Jean-Louis Adam’s position and status as a nurseryman active within the Parisian plant trade, a surprising degree of doubt and scepticism was attached to his testimony on how the tree had been produced in his nursery. This doubt, I argue, helps us to trace the complex negotiations of authority that constituted debates over plant heredity in the early 19th century and that were introduced with a new generation of gardening and horticultural periodicals.

Collecting seeds and specimens was an integral aspect of botany and natural history in the eighteenth century. Historians have until recently paid less attention to the importance of collecting, trading and compiling knowledge of their cultivation, but knowing how to grow and maintain plants free from disease was crucial to agricultural and botanical projects. This is particularly true in the case of food security. At the close of the eighteenth century, European diets (particularly among the poor) began shifting from wheat- to potato-dependence. In Britain and Ireland during these decades, extensive crop damage was caused by diseases like ‘curl’ and ‘dry rot’ – leading many agriculturists and journal editors to begin collecting data on potato cultivation in order to answer practical questions about the causes of disease and methods that might mitigate or even eliminate their appearance. Citizens not only produced the bulk of these data, but also used agricultural print culture and participation in surveys to shape and direct the interpretation of these data. This article explores this forgotten scientific ambition to harness agricultural citizen science in order to bring stability and renewed vitality to the potato plant and its cultivation. I argue that while many agriculturists did recognize that reliance upon the potato brought with it unique threats to the food supplies of Britain and Ireland, their views on this threat were wholly determined by the belief that the diseases attacking potato plants in Europe had largely been produced or encouraged by erroneous cultivation methods.