The above considerations, I trust, make it clear to the reader, what are the kind and the extent of the knowledge of the empirical bone-setter. I am not disposed to say that he has no knowledge at all. He has power to observe, though his means of observation are limited, and therefore his knowledge is limited, and of consequence inaccurate. He acquires all the knowledge which he has by observing (and that is studying) the external geography of the joints to which I have alluded. He may perhaps have an accurate eye in such matters, or, as a phrenologist would express it, he may have the organ of form well developed. If this be true of him, in many cases of dislocation he will readily see where the irregularity is. He will see an undue prominence at one point and a consequent depression at another. The knowledge thus acquired by the eye guides him in his practice. He pulls the bones apart, and then applies pressure in such a direction, as to force in the prominence, and remove the depression. This is the sum and substance of all that an uneducated bone-setter can know, and his knowledge all comes from observation, and is not the result of any mysterious gift. It is folly to pretend that the empirical bone-setter cannot, by the study of the internal structure of the joints, add to his knowledge and skill thus acquired from observation of their external forms. And yet he assumes, and a large portion of the public believe it, that not only does his skill, unlike skill in anything else in the wide world, need no adding to it, but that it would be actually impaired by anything like scientific study. That his _reputation_ would be impaired very seriously, if it were publicly known that he in any measure acknowledged the necessity of study, is certain; for his skill would then be stripped of the charm, which is given to it by the idea of its being an innate power. It is for this reason only that he adheres so pertinaciously to this false and ridiculous notion. I have thus far gone upon the supposition, that the natural bone-setter learns all that he knows by his own observation alone, without any assistance from others. This is far from being true. He is indebted to physicians themselves for some of his knowledge. For example, the fact that extension and counter-extension[22] must be made to enable us to put the dislocated bone into its place, is not a fact that he discovered. Somebody, (we know not who, but it was somebody,) discovered it a long time ago, and the knowledge of it has descended in the medical profession from time immemorial. It is in this channel that the knowledge of it comes to the bone-setter. He might as well say that it was an innate idea with him, that knives and forks are the appropriate instruments to eat with, as that he was born with the knowledge of the fact, that the expedient which I have mentioned is necessary in setting dislocated bones.