The paper focuses on the role that instruments played in the medical discourse of the 19th century. Towards the end of the century, instruments had imbued the medical sciences to such an extent that the situation soon was compared to the vernacular confusion of the biblical tower of Babel. Whereas the autonomical recordings of laboratory apparatus, vouched for guarantee against biased test results, clinicians and general practitioners were finding it difficult to incorporate the new techniques into their daily routines. A tension between the instrument as invention, moulded to fit a particular series of experiments, and the instrument as a reproducible item, was inevitable. Hence, the unification of the science and practice of medicine, became an important topic at the international medical meetings of the late 19th century. Seen in the light of the industrialization and urbanization of occidental culture and society, the instrumentation of medicine entailed a number of significant issues which hinged on the relationship between the biological destiny of man and the artificial wonders of technology. Grand metaphors like the organic machine and the human motor, did not only signal a scientific preoccupation with the shortcomings of the living organism as opposed to the perfection of the machine, but also indicated closer ties between the human body and technology at large. In a certain sense, medical instruments, along with apparatuses such as the camera, the steam-engine, the telegraph, the phonograph and the cinematograph, offered a new set-up of codes with which the body and its functions could be reinterpreted. In this respect, the late nineteenth-century strive for the standardisation and unification of medical instruments, was not irreconcilable with the notion of the l'homme moyen, as conceived, for example, in the work of the Belgian mathematician Adolphe Quetelet. The paper outlines the span of medical measuring devices, dating from the sphygmometer of Jules Hérisson to the technical obsession of the late 19th century physiologists. During the course of fifty years, the purpose of Hérissons instrument, to achieve a common nomenclator for the evaluation of human blood pressure, had been driven to its extreme. Fascinated with the wonders and possibilities of sheer technology, physiologists cultivated the cult of the instrument to such a degree that the very evidence of organic phenomena, was transfigured into graphical projections, the monotonous of the telephone and other technical manifestations.