THE CHEMISTRY OF URINARY STONES AROUND 1800 - A FIRST IN CLINICAL-CHEMISTRY

At the end of the 18th century, as soon as modern chemistry was created, dedicated physicians tried to apply it to medicine. A rewarding field was that of urinary lithiasis. Stones offered a sufficient amount of a relatively pure chemical present in the body. Indeed, urine and the solidified matter was within the analytical grasp of the existing techniques. The first step was made by Scheele in Sweden who identified uric acid in calculi and normal human urine. During the following thirty years, Fourcroy and Vauquelin in Paris and Wollaston, Pearson, Marcet and Prout in London identified the various salts, uric acid, urate, various phosphates, oxalate, calcium, ammonium and magnesium forming current calculi. The conditions of their solubility in vitro were described. Even rare components such as cystine and xanthine were unraveled in London. The impetus given by these studies offered a good start to clinical chemistry in general and to the understanding of urinary lithiasis in particular. This led to the discovery of the corresponding solutes in the urine of such patients. Unfortunately, during the following decades nothing was added to these chemical investigations, and most of what had been acquired was forgotten. Research was concentrated on clinical pathology The implementation of chemistry to medicine had to wait.