A urine-diverting dry toilet (UDDT) is a type of dry toilet with urine diversion that can be used to provide safe, affordable sanitation in a variety of contexts. of ionized calciun1,Yhen normal urine,Yas com- pared to urine from stone- forming patients. 5. Thomas and HmYard reported that ionized calcium constituted J. C.W. Vermeulen, G.H. Miller, W.H. ChapmanExperimental urolithiasis: X. On the state of the calcium in the urine. J. Urol., 75 (), p. 6. W.C. Thomas Jr.