Appendix 2 Notes on Classifications and Drawings of Nephritic Kidneys in the Nineteenth Century

Abstract

It is axiomatic that in the absence of acceptable descriptive terms that could be replicated, drawings of nephritic kidneys were a priceless asset and provided the greatest contribution to our present-day image and understanding of the types of lesions that the nineteenth century renal physicians were depicting. Although injected Malpighian corpuscles or glomeruli could be seen on the surface of the kidney using a hand lens (Rayer described them as ‘‘petits points rouges’’), prior to microscopic examination workers could only report on the crude morbid anatomical appearance of the kidney. The terms used related to size, weight, shape, colour, hardness, adherence of the capsule and the presence or absence of granulations. It is difficult to assess the value of contemporary classifications of the time unless the findings are accompanied by drawings and all the best studies did so, including those of Rayer, Bright and Martin Solon. If we compare Rayer’s extended six-form classification of nephritic kidney with Bright’s original three forms some interesting facts emerge. Most nephritic patients, other than those who survived scarlatina nephritis and were unavailable for ‘‘observations’’, died, often at different stages of the disease perhaps days, weeks or months after the onset of the nephritic process. The latter would explain the disparity in the appearances of the kidney. Bright described the three classical forms corresponding to three clinical presentations which we have simply dubbed as the ‘‘large red’’ of acute nephritis, the ‘‘large white’’ of the nephrotic syndrome and the ‘‘contracted granular’’ of chronic end stage nephritis, and remained agnostic about the existence of any other forms. Modern nephrologists are agreed that it would have been difficult at that time to improve on Bright’s classifications. One can identify these three forms within Rayer’s collection of six forms. With the advantage of hindsight it is tempting to postulate that Rayer’s extra three forms were merely examples of the Bright three but at different stages of the disease process, for example sub-acute nephritis. This hypothesis cannot be proved as nowadays nephritic patients do not usually come to post mortem and it is difficult to compare present-day biopsies with the nineteenth-century morbid anatomical appearance of the kidney. This theory may be further considered by examination of Rayer’s and Bright’s classifications and their accompanying plates. Rayer is at great pains to express in words the differences and alterations that he discusses during his post mortem ‘‘observations’’ and from his illustrated plates. The descriptions tend to be over elaborate as he searches for intermediate changes that extend the spectrum of Bright’s three basic kidneys. He places a good deal of emphasis on lobulation, which we now know is a normal variant but which could have been accentuated in a swollen kidney. Although it can never be conclusively proven it is likely that as the chronic disease process progressed whether from a large white or red type, the kidney became more