Almost equally famous as a surgeon, though by no means such an omnivorous student as Hunter, was Benjamin Bell, of Edinburgh, who died in 1806. He employed tubes of lead and silver for the purpose of drainage. Sir Charles and John Bell, also of Edinburgh, are eminent names pertaining to the latter part of the eighteenth and first part of the nineteenth century. The latter was Professor of Anatomy, Surgery, and Obstetrics, a busy practitioner, a fertile writer, and not only one of the most successful operators of his day, but an excellent classical scholar;{219} his _Principles of Surgery_ appeared from 1801 to 1807. Sir Charles, who died in 1842, belongs more to the present century, but was equally distinguished as an operator, surgeon, and writer, and best known, perhaps, lor his _Bridgewater Treatise on the Hand_. Among the Dutch an eminent surgeon was Peter Camper (1722-1789), who, in order to acquire manual dexterity, learned to use various mechanical tools. He was a fruitful author, and did not consider it beneath his dignity to write a treatise about the best form of shoes, published in Vienna in 1782, but recently translated and republished in England as something new. Sandifort, of Leyden, discussed ruptures, dislocations, etc., and reported the first observation of downward dislocation of the femur. As already noted, the surgeons of the eighteenth century were often obstetricians,--William Hunter conspicuously. The{220} most important obstetrician of his time was William Smellie (1680-1763), of London, who invented numerous instruments, wrote a large treatise on the theory and practice of midwifery, and greatly advanced our knowledge of deformed pelves. He was the first to distinguish one diameter from the other, and to point out the importance of cephalic version and version of the breech. Parenthetically, it may be remarked that William Hunter, great as he was, was the uncompromising foe of instrumental midwifery, and was in the habit of showing his forceps, covered with rust, as evidence that he never resorted to such aids. A rival of Smellie and Hunter was Thomas Denman (1753-1815), best known, perhaps, because of his demonstration of the portability of puerperal infection.