[Historical Archives of Italian Nephrology. The history of instrumentation in nephrology. Part II: microscope and haemodialyzer].

Medicine in the technological era acquired many of the characteristics that concurrently marked other fields. So, by adopting procedures based on information obtained with instruments and devices, medicine developed an approach to illness that transformed it into a special form of technology. The collective effect of instrumentation deserves consideration and offers the historian opportunities for interpreting the interaction between physician and his patients in other than scientific and technological terms. The very construction of instruments and devices depends on the Author's ideas assembled with the basic theories of the time. For instance, at the end of the nineteenth century, when medical instruments became essential, the bacterial origin of diseases revolutionised their construction and application. In this context, the invention and use of the microscope became an outstanding feature of the clinical approach by disclosing the cellular universe. The microscope had become crucial in locating some major causes of physical suffering and death in man, and was considered the pre-eminent diagnostic instrument in medicine. In the nephrological field, the microscope drew the physician into a universe of physical changes that were concealed to the naked eye. The microscope made possible the verification of some of Bright's brilliant ideas, something that helped physicians classify glomerulonephritis. Many nephrologists confessed "how few things are established in this subject (nephrology) and how many more difficulties are established, we have learned by experience with the microscope". The modesty of this claim is striking. In nephrology, as in other fields, the admission of ignorance proved to be the beginning of wisdom. This wisdom, based on the admission of ignorance and assembled through the commitment and ingenuity of the pioneers of the dialysis treatment, led to the treatment of end-stage renal disease and the guarantee of success. The technique of haemodialysis has been enriched by the new lexicon, which expresses different ways and ideas on the removal of the solute.