Corrosive sublimate and its introduction as an insecticide for preserving natural history specimens in the eighteenth century

Abstract

By the mid-eighteenth century, the need to protect zoological and botanical collections from attacks of insects became pressing for the community of naturalists. Living ornamental and economically important plants and their seeds also needed to be protected from insects when transported by sail. John Ellis ( c.1710–1776), one of the pioneers of plant transportation, was instrumental in disseminating the knowledge of insecticidal properties of corrosive sublimate (mercury(II) chloride or mercuric chloride, HgCl2). Although the use of corrosive sublimate for the protection of zoological collections had been proposed by John Woodward (1665–1728) in 1696, it was probably not widely used by naturalists until Ellis had published his Directions for bringing over seeds in 1770, recommending this substance for the protection of living plants, seeds and specimens during transport. Ellis possibly learned about the insecticidal properties of corrosive sublimate from the emerging use of this compound to control bedbugs ( Cimex lectularius). The history of bedbug management in eighteenth-century London, and some early exterminators, including John Southall ( fl.1726–1738), George Bridges ( c.1695–1768) and Thomas Tiffin ( fl.1760–1783), are discussed. Only a few days after the Directions was printed, Ellis asked Thomas Davies ( c.1737–1812) to publish a method of preparing bird skins that involved corrosive sublimate and was probably involved in drafting it. Following these two publications, corrosive sublimate was frequently used for the preservation of natural history collections including bird skins and herbarium specimens.