47. The ancients, though less informed than we are respecting the nature of these causes, knew better how to appreciate their effects. All their forms of apparatus made a permanent extension, a measure which has been abandoned by most of the moderns, and regarded, even at present, in France, by a great number of practitioners, as always dangerous, and seldom useful. Let us set in opposition to the vain fears which it inspires, a few thoughts, and much experience. 48. It is from the very object which is proposed to be attained, that the first difficulties arise. What must we think of a limb in a state of preternatural tension, where all the parts being overstretched must experience an uneasiness not to be supported? I answer, that it is not a preternatural elongation that extension produces; on the contrary, being intended to prevent a preternatural shortening, it has for its object to restore the parts to their ordinary state, and to give to the muscles their habitual degree of tension, by opposing such contractions in them as are not habitual: under this point of view, it performs, in relation to the muscles, those very functions which are discharged by the bone itself, when sound and unbroken, as is fully experienced by all patients, when the apparatus is applied. Its use not only does not increase pain, but is alone calculated to diminish it, because, by bringing the fragments into apposition, it prevents the soft parts from being irritated by the points of the bones. 49. Is the swelling of the limb to be dreaded, as some pretend? But whence can this swelling arise? From the over-stretching of the parts? I have already proved that they are not over-stretched. From the pressure of the straps? Perhaps this cause might produce a swelling, if, as formerly, it were applied above the knee; but, by placing it, as Desault did, near to the ancle, by surrounding, with a thick compress, the lower part of the leg, where the straps pass, and by securing the foot with a tight bandage under the straps, if their action be dreaded, this fear must be done away; and, besides, experience, which is the only true test of the dangers of a process, by no means justifies the apprehension. The venæ saphenæ and the absorbents that accompany them, are free from the compression, which bears principally on the tendo Achillis, and the malleoli.