The history of urinary microscopy to the end of the 19th century

In the 17th and 18th centuries, several authors performed urinary microscopy occasionally and were often unable to give their observations a practical diagnostic application. Such men included De Peiresc, Boerhaave, Ledermüller and Galeazzi. In the 1st half of the 19th century, however, urinary microscopy began to be used systematically. Rayer and Vigla identified for the first time elements other than crystals in urine and contributed to the methodology of handling samples for microscopy. Becquerel described dysmorphic erythrocytes, and Simon and Henle observed casts in urine and in histological preparations. In contrast, Bird mentioned casts only in passing, though he described many other elements and published the first complete book on urinary microscopy. The 2nd half of the 19th century was characterized by further advances, and in the book of Beale tubular cells were distinguished from other epithelial cells. Different types of casts were also linked with different renal diseases. By 1875 the classification of casts was complete. The work of the 19th century microscopists culminated in Rieder's book on clinical microscopy, which described each element of urinary sediment through 36 beautiful chromolithographic plates.