JAMES MONCRIEFF ARNOTT, who endowed these demonstrations in 1850 during the year of his first Presidency of the College, was elected to the staff of the Middlesex Hospital in 1831, and was one of the founders of its Medical School in 1835. He was chief amongst those who insisted on an eight-day holiday for medical students from Christmas Day to New Year's Day inclusive. An early advocate of the need for specialization in surgery, he undertook in 1843 the duty of running an ophthalmological out-patient clinic in addition to his general surgery. He was a strict disciplinarian but had a dry sense of humour. It was recorded that on a teaching round, after showing a newly invented instrument most completely fitted for the desired purpose, he ended by saying, ' In fact, gentlemen, it is one of those ingenious conceptions which is of no use.' There are many ingenious conceptions in the collection of Historical Surgical Instruments in this College; some are now ' of no use', but many are the precursors of modern instruments and serve as historical landmarks in the development of surgical technique. In no branch is this more evident than in the surgery of stone in the bladder and it seems appropriate to base this account of the history of the operations devised for it on the instruments used. Stone in the bladder has been known since the earliest times. Elliot Smith discovered a stone in the pelvis of a skeleton in the grave of a pre-dynastic Egyptian at El Amara; it was described by Shattock (1905) and was estimated to be more than 7,000 years old. It was in the museum here until 1941, when it was effectively crushed and completely dispersed by enemy bombs.