Hans Sloane (1660–1753) has all but been forgotten by the general public, only remembered by a few London street names. This was not helped by the fact that the British Museum, which was formed from the vast bulk of Sloane's collection, did not bear his name. Concentrating on the long life of one of Britain's most significant collectors, James Delbourgo's admirable biography explores several themes surrounding Sloane and his vast collection comprising natural history, antiquities, ethnography, mathematical instruments, coins and medals, drawings and a library of over ten thousand volumes. Born in 1660 to Scottish Presbyterian parents in Ulster, Northern Ireland, Sloane's life spanned from the Restoration of the monarchy to the onset of Britain becoming a global economic power by the 1750s. In 1679 Sloane left Ulster for London to train as a physician, attending Gresham lectures and making acquaintances with figures such as Robert Boyle, William Courten and John Ray. Four years later, Sloane embarked on a tour of the European continent, during which he met Joseph Pitton de Tournefort and gained a medical degree from the University of Orange. After his return, Sloane was appointed the principal physician for James II's new governor of Jamaica, the Duke of Albemarle, which resulted in his trip to Jamaica from 1687 to 1688. Sloane spent a total of fifteen months in Jamaica, a trip which truly opened his eyes to expanding commercial interests and natural history, essential inspiration for the formation of one of the largest collections of the age.

A central theme of Collecting the World is Sloane's interests in empire and collecting, taking his Jamaican trip, which shaped much of his later life, into account. On this dangerous voyage, Sloane's main task was to attend to the medical needs of the Duke of Albemarle and his family, although, due to the duke's poor health and early death in 1688, Sloane was able to use the time to explore the natural history of Jamaica. Sloane treated the English planter elite and the African slave population when he toured the plantations, including that owned by the first husband of his future wife, Elizabeth Langley Rose.

As it did in Sloane's lifetime, slavery plays a key part in this book. Not only did Sloane provide medical treatment for slaves in Jamaica, to satisfy their owners who were afraid of potential economic losses, but after his marriage he became the administrator of his wife's first husband's Jamaican sugar plantations, which provided a substantial income. However, Sloane also made vast amounts from his medical practice; land investments in and around London, including his purchase of Chelsea Manor from Lord Cheyne in 1712; and shrewd investments in joint-stock companies. This income allowed Sloane to capitalize on his interests in natural history, resulting in the publication of his expensive two-volume work, A Voyage to the Islands Madeira, Barbados, Nieves, S. Christophers and Jamaica, with the Natural History of the Herbs and Trees, Four Footed Beasts, Fishes, Birds, Insects, and Reptiles, &c. of the last of those islands (1707–1725), based on his observations, specimens and artefacts gathered in Jamaica. These evidently formed the foundation for Sloane's main collections, which grew considerably in the decades following 1700.

Delbourgo details how Sloane, rather than collecting the majority of his objects himself, tended to collect the collections of his deceased colleagues, contemporaries and rivals, perhaps the most prominent being that of the London apothecary James Petiver, which Sloane purchased for £4,000 in 1718. Additionally, he acquired objects through a global network of correspondents stretching from Tierra del Fuego to Japan. Examples include Daniel Waldo from Gujarat; Alexander Stuart, who sent Sloane specimens from China, Borneo and the Malay Peninsula; James Cunninghame, a Scottish physician working in China; Mark Catesby from North America; Henry Elking from Northern Canada; William Dampier, a privateer who travelled to New Holland and the Pacific; and Benjamin Franklin, who gave Sloane several ethnographic artefacts from North America. The addition of forty-two colour figures along with numerous black-and-white images of the many objects and manuscripts described in the main text allows the reader to understand the extent of the collection and the objects it contains. Delbourgo has often gone to extensive lengths to trace the stories of these objects from their original localities to their placement in Sloane's museum, describing a global network of transactions whilst providing a rich framework for understanding the development of an eighteenth-century collection.

A main point explored in Collecting the World is the internal workings of Sloane's collection, listing numerous amanuenses and catalogues, which tended to serve as accession registers. Sloane's vast legacy of ‘scraps’ of paper, in the form of specimen labels and catalogue entries, provides an insight into the rational and complex systems of information management which surrounded these objects. Sloane's ‘renaissance’-style cataloguing system (p. 261), which broadly followed divisions developed in the sixteenth and seventeenth centuries, was combined with precise cataloguing and classificatory systems of the Enlightenment. It is clear, then, that Sloane's collection truly sat on the crossroads between irrational assemblages of objects and rational Enlightenment practices. Delbourgo's discussion opens the way for further work in this area, allowing for the development of a more detailed understanding of how different entities such as catalogues, printed books, labels, physical spaces and the objects themselves interrelated and united Sloane's collection as a whole.

Following Sloane's death in 1753, the collection was purchased by the British parliament for £20,000 and became the foundation of the British Museum, a global legacy that remains in the form of the British Museum, British Library and Natural History Museum. I hope that Collecting the World will make Sloane's collection and legacy known among more general readers. For historians of science, Delbourgo has made an important contribution to the intertwined themes of empire and scholarly collecting.