John Chiene, Encyclopædia Britannica, Ninth Edition (1888)
“ When such concretions are so small that they can be passed with the urine through the urethra they are known as gravel; but when they are prevented by their size from passing along the urethra they are termed calculi, and the patient is said to suffer from stone or calculus. Calculus of the bladder constitutes a most formidable and important disease, and its treatment, either medical or surgical, has probably attracted more attention than that of almost any other disease. Urinary calculi occur in all parts of the world and affect both sexes. ”
