3. Whatever may be their cause, they generally occur in such a manner, that a longitudinal division separates the condyls from each other, and, extending upwards to a greater or less distance, is terminated by another transverse or oblique division, which passes through the whole thickness of the body of the bone, so that there are three fragments, and two fractures. 4. Sometimes the division is simple; in which case, being directed outwards or inwards, it crosses the lower end of the humerus, obliquely from above downwards, and terminating at the joint, separates but one of the condyls from the body of the bone, leaving the other adhering to it. 5. In the first case (3), there is more deformity at the broken extremity of the humerus; and the mobility is also greater. If the fingers, placed before or behind, press on the limb in the direction of the longitudinal fracture, the two condyls will be separated from each other, the one yielding in an outward, and the other in an inward direction, leaving a fissure or opening between them. The part at the same time expands in breadth. Thus, the two condyls of the os femoris, are seen to separate from each other when in a similar fracture, pressure is made on the rotula. The fore-arm is almost constantly in a state of pronation. When we take hold of one of the condyls in each hand, and endeavour to make them move in opposite directions, they can be brought alternately forward or backward: and, if their surfaces touch, a manifest crepitation is heard. 6. In the second case (4), the condyls cannot be so easily separated from each other; but it is always practicable by taking hold of that one which is divided from the body of the bone, and moving it from before backward, to produce a crepitation, which is a sufficient proof that a fracture exists. In a case where the external condyl was alone separated, Desault found the limb in a constant state of supination, a position to be attributed, without doubt, to the muscles attached to this condyl. 7. An acute pain, the almost inevitable effect of the flexion or extension of the fore-arm, the habitual semi-flexion of the limb, a tumefaction of it sometimes supervening, and a swelling more or less considerable, around the joint, are symptoms which accompany both modes of division (3 and 4). The fracture may further be rendered complicated by means of wounds, splinters, &c. when the blow has been very severe, or when a pointed fragment has made its way through the surrounding soft parts, &c. § II. OF THE PROGNOSIS. 8. The preceding assemblage of signs, leaves in general but little doubt on the subject of the diagnosis; but is the establishment of a solid prognosis attended with the same facility?