The development and evolution of “cerebral thermometry”: The physiology underlying a nineteenth-century approach to cerebral localization and neurological diagnosis

ABSTRACT

Surface thermometers were developed in the latter half of the nineteenth century. From the 1850s through the 1880s, collaborations between physicians, research scientists, and instrument makers produced clear improvements in the technology to measure cranial surface temperatures, with development of self-registering mercury surface thermometers resistant to pressure and little influenced by ambient temperature, apparatus for recording cranial surface temperatures from multiple stations simultaneously, and development of thermoelectric apparatus. Physiologic studies of cranial surface thermometry were conducted over a quarter century from 1861 to 1886. Beginning in the 1860s Albers in Bonn, Germany, and Lombard at Harvard and later in England systematically investigated surface temperatures on the head using surface thermometers and thermoelectric apparatus; they demonstrated that head temperatures were variable over time and across individuals and were not clearly influenced by thinking or muscular contraction but were influenced by ambient air temperature. In 1880 Amidon in the United States claimed that cranial surface thermometry during exertion produced localized increases in surface temperature on the contralateral scalp in a specific pattern (“external motive areas”) indicating underlying brain areas responsible for each movement. Amidon’s results were not reproduced by experienced physiologists in England or France. Contemporaries recognized that significant technical and practical problems limited the accuracy and reliability of cranial surface thermometry. Physiological studies of cranial surface thermometry ended in the mid 1880s, although some clinicians who were early advocates promoted its use in clinical contexts into the early twentieth century.     

The development and evolution of “cerebral thermometry”: Clinical applications of a nineteenth-century approach to cerebral localization and neurological diagnosis

ABSTRACT

Surface thermometers were developed in the latter half of the nineteenth century. In 1877, Broca, already famous for his contributions to the cerebral localization of nonfluent aphasia, presented his first clinical observations on cranial surface temperatures: In two cases, cranial surface temperatures were decreased over a middle cerebral artery infarction, and increased in surrounding areas, which Broca attributed to “compensatory hyperaemia.” As Broca made apparent in a later report in 1879, he had used a “thermometric crown,” an apparatus consisting of six to eight large-reservoir mercury thermometers strapped against the head. Following Broca’s report, American neurologists reported cases in which cranial surface temperatures were increased either locally over a superficial brain tumor or globally with a cerebral abscess. Despite promising anecdotal reports, contemporaries recognized that significant technical and practical problems limited its accuracy, reliability, and clinical utility. Advocates never demonstrated that this technology provided significant marginal benefit to the medical history and physical examination. The technique fell out of fashion before 1900, though some early advocates promoted it into the early twentieth century. It was ultimately replaced by more effective technologies for cerebral localization and neurological diagnosis.     

The assessment of Perkins’ patent metallic “tractors”: Abandonment of an 18th-century therapeutic fad following trials using sham instruments

ABSTRACT

From 1799 to 1801, with the instigation of John Haygarth, physicians in England evaluated the claims of Elisha and Benjamin Perkins that their patented “metallic tractors” could cure a wide variety of disorders. Previous therapies were typically judged based on experience and authority, whereas Perkinism was evaluated using a series of clinical trials of varying methodological sophistication, most employing sham instruments (all but those involving infants or horses), with a variety of trial designs, inconsistent use of contemporary controls, and different approaches to blinding subjects to the treatment administered. Haygarth and his colleagues collectively demonstrated that tractors and sham instruments produced equivalent effects in adults, and, by inference, that the tractors had no special therapeutic properties. Other trials using only genuine tractors demonstrated no effects in infants and horses, subjects who could not reasonably be influenced by suggestion and the imagination. These collective results provided strong support for the rival hypothesis that the observed effects were due to suggestion and the imagination of the subjects. Despite fallacy-laden counterattacks and counterarguments from Benjamin Perkins and his supporters, the trials eroded support for this therapy and led to abandonment of the “Metallic Practice” as a treatment in Britain and elsewhere.     

The Southern Conservative Thought of John C. Calhoun and the Cultural Foundations of the Canadian Identity

Besides the largely ignored fact of general Canadian support for the Southern Confederacy during the American Civil War, the consociational dimensions of Canadian Confederation, as something opposed to American unionism in cultural terms, finds its historical roots legitimized in the Southern conservative writings of John C. Calhoun. It is the tension between an institutionally entrenched foundation of consociational pluralism and growing urban cosmopolitanism within Canadian history that has defined the debates and divides over the meaning of the Canadian identity, just as it is. Alternatively it is the tension between enforced constitutionalist unionism and consociational cultural tradition within the American South that has largely defined their historical experience. Both Canada and the American South find the tensions of their cultural identities rooted in the consociational values originally laid out by nineteenth century Southern conservative political thought.