Secondly. The uneducated bone-setter is very liable to make a mistake in those cases in which, though there may be much tumefaction and pain, and the motion of the joint may be much impeded, there is neither dislocation nor fracture. Of all the cases of injury of the joints a very large proportion are of this character. There is simply a sprain or a bruise, or both together. Such cases the bone-setter almost invariably treats as dislocations. I will not at present dwell upon this class of cases, as I shall speak of them more particularly in another connexion. I will only remark here, that if the bone-setter does but little in such cases, no real harm may be done; but he may use so much violence, in reducing the supposed dislocation, as to inflict a serious injury upon the joint. Thirdly. Another class of mistakes, to which the uneducated bone-setter is liable, have relation not to the mechanical principles of bone setting, but to what may be called the _medical_ in distinction from the _surgical_, or operative part of the treatment. The mere operator, however skillful he may be, is not a finished surgeon. Very far from it. In order to be able to do his _whole_ duty to his patients, the surgeon must in addition to his skill in operating, understand well the principles of inflammation and irritation, and must be in fact familiar with the whole range of disease. The bone-setter is entirely destitute of any such qualification for his department of surgery. He looks upon every case as a mere mechanical matter, and operates upon it without any regard to the state of the patient’s health, or to any of the circumstances of the case. He therefore operates upon many cases that ought not to be operated upon, and does to them a serious injury, sometimes a fatal one. In some cases he neglects to do what is necessary for the relief of the patient, and prevents any one else from doing it. It may be that inflammation needs to be guarded against, or to be overcome. This he neglects to do; and not only so, but perhaps, by the violence which he does to the affected part, he aggravates, or creates inflammation. The same may also be said of his neglecting the prevention and cure of spasmodic affections. I will cite but a few cases illustrative of the above remarks.