We will now notice some of the instruments which are most useful in dissection. Two or three different sizes of ordinary scissors should be possessed, but the shapes must be modified in others for many purposes, as those used by surgeons; a pair with the cutting parts bent in a horizontal direction, and another pair slightly curved in a perpendicular; so that parts of the substance operated upon may be reached, which it would be impossible to touch with straight scissors. One point of these is sometimes blunt, and the other acute, being thus made very useful in opening tubular formations. Another form of these is made, where the blades of the scissors are kept open by a spring, the handles being pressed together by the fingers. Where it is desirable, one or both of these handles may be lengthened to any degree by the addition of small pieces of wood. THE KNIVES which are most useful are those of the smallest kind which surgeons employ in very delicate operations. These are made about the length of an ordinary pen-knife, and are fixed in rather long flattish handles; some are curved inwards, like the blade of a scythe, others backwards; some taper to a point, whilst others again are broad and very much rounded. Complete boxes are now fitted up by the cutlers, of excellent quality and surprisingly cheap. NEEDLES.--These are very useful and should be firmly fixed in handles as recommended in Chapter I. It is convenient to have them of various lengths and thicknesses. If curved by heating and bending to any required shape they may be re-hardened by putting them whilst hot into cold water. Dr. Carpenter also makes edged instruments by rubbing down needles upon a hone. They are more pleasant to work with when _short_, as the spring they have whilst _long_ robs them of much of their firmness.