Composition of Urinary Calculi by X‐ray Diffraction: Collected Data From Various Localities

SUMMARY The composition of 88 male, 12 female and 12 juvenile stones (including the one from Emperor Napoleon III) from the Sir Henry Thompson collection of bladder calculi has been determined by X‐ray powder methods. An unusual substance identified is calcite. Uric acid is the major constituent of the adult stones and ammonium acid urate of the children's calculi. Comparison of the adult stones with a similar collection from the Norwich Hospital Museum shows that the Sir Henry Thompson collection contains less uric acid and more phosphates.