Winter's book, in ostensibly telling a history of mesmerism, offers a cultural history of the making of medical knowledge. Much of her discussion focuses on debates over how to establish or recognize scientific and medical authority, and how arguments over how mesmerism worked, if it worked, and its status as a "natural" or "unnatural" phenomenon, for example, shaped the development of scientific authority and the definition of scientific evidence in the Victorian period.

Much of this book turns on the question of power. Winter's analysis of the shifting power relations between mesmerist/physician and subject/patient beautifully demonstrates the vexed nature of medical authority during the early Victorian period, especially when mesmerized subjects commonly functioned as clairvoyants who could "diagnose" a distant patient's disease. Furthermore, she offers nuanced discussions of how the power dynamic inherent in Victorian class, race, and gender differences inflected the various types, effects, and cultural meanings of mesmerism.

Her chapter on mesmerism in India, for example, demonstrates the various questions of power that mesmerism raised--for example, the contested, but central, role of mesmerism in enabling the surgeries needed to treat "exotic" colonial diseases like elephantiasis; the freedoms and constraints of medical practice at the colonial peripheries; and the concerns raised when Indian medical attendants were enlisted to perform the exhausting task of mesmerizing patients for surgery, since the process was thought to require close physical proximity and near-nudity.

Winter also analyzes the gendered meaning of mesmerism, in particular its potential as an alternative to, or an enhancement of the power of, invalidism for intellectual women like Ada Lovelace, Harriet Martineau, and Elizabeth Barrett Browning. Not surprisingly, mesmerism's sometimes dramatic effects on such "nervous" patients provided ample ammunition for critics of the practice. Similarly, mesmerism raised questions about the social expression of sexuality. Besides the obvious concerns over a mesmerist's potential control of his subject's body, Winter includes other examples: Martineau, for instance, was criticized for telling the public, in her writing on mesmerism, about her uterine cancer.

Overall, Winter clearly demonstrates early Victorians' implicit belief that mesmeric influence worked in concert with gender, class, and race hierarchies, with women, servants, the Irish, and the Indians more susceptible than educated, professional white men of the upper classes.

In connection with her interest in mesmerism as a trope for "influence," she discusses Charles Dickens's strong interest in mesmerism, his role as a "conductor" of a community of readers, and Wilkie Collins's similarity to a mesmerist in his ability to stimulate the physiological responses of readers through his sensation novels. She includes a brief discussion of the similarities between fears over mesmerism and fears over novel-reading late in the century.

Winter frequently foregrounds the common anxiety, over mesmerism's effects on authority and the will, in particular the mesmerist's threatening ability to override the will, and, later in the century, the concern that the mesmeric experience, and other "consensual" states in which the will was suspended, would sap the judgment and mental acumen of the British public. The threat of mesmerism, she argues, inspired educational reforms designed to discipline the mind through scientific training, so that the British citizen could differentiate between valid scientific authority and frauds.

She also focuses on the subtle shifts in the meaning of "consensus," leading to the ability of the mesmeric "conductor" to focus the will of a public group without stripping each individual of his or her judgment. Winter's central thesis, in fact, argues that mesmerism provoked and localized simmering debates among Victorians about authority, professionalism, will, judgment, morality, knowledge, evidence, consciousness, and other fraught terms and concepts.

Pain takes on new meaning in one particularly interesting thread that Winter coaxes from the history of mesmerism. Certainly many patients tried mesmerism as a possible way to relieve pain, and Winter's description of mesmerism's role in provoking researches into chemical anesthesia is fascinating. But pain also functions as a form of proof or disproof in the history of mesmerism. In discussing the early experiments in animal magnetism, Winter dwells on how mesmerists virtually tortured their patients in their efforts to demonstrate the "reality" of the mesmeric trance to a skeptical audience. She also argues for the importance of pain in defining surgical authority at mid-century, and that mesmerism threatened to unsettle that authority in crucial ways even as it seemed to open up new opportunities in surgery.

Winter's book is long and seems at first to make almost incredible claims about mesmerism's role as a catalyst in the development of a dazzling range of Victorian cultural forms. Overall, however, she offers a convincing reading of how mesmerism affected Victorian ways of science, medicine, race, nation, gender, class, religion, marketing, literature, music, and politics. The book also features an array of memorable period illustrations and an exhaustive, very useful bibliography.