Xanthine Calculi are exceedingly rare. The substance is allied to uric acid, and the stones are like those of uric acid but of a redder colour. On applying the murexid test to a fragment of such a stone, it is found to dissolve in nitric acid but without effervescence; the addition of ammonia gives an orange colour.

Literature

Rupture - Bitinqton, (with literature) Rupt. of urinary bladder, 1884; Coats, Brit. Med. Jour., 1894, ii., 121. Cyntitis - Ebstein, Ziemssen's Handb., ix.; Dc'Mesnil, (Gonorrheal infl.) Virch. Arch., cxxvi., 1891. Tuber-culosis - Kbzywicky, Ziegler's Beitr., iii., 1888; Chavasse, Etude gar la tub. des org. urinaires, 1872; Voisin, Bull, de la soc. anat. de Paris, xlix., 1874. Tumours - Thompson, Tumours of bladder, 1884; Kuster, Volkmann's klin. Vortr., 267, 268, 1886; Albanan, Turn, de la vessie, 1892; Cahen, (Cystadenoma, cancer) Virch. Arch., cxiii.; Tschistowitsch, (Growth of papilloma) ibid., cxv.