When, in consequence of a blow or fall, one or more teeth have become loose so that the patient cannot bite his food with them, if the use of styptic remedies has been found of no use, it will be necessary to bind and make such teeth firm by a gold or silver wire. Gold is to be preferred as being unalterable, whilst silver in a few days turns green. Having chosen, therefore, a suitable gold wire of perfectly uniform consistency, it must be passed at its middle part between two firm teeth, that is between the two nearest on one side to the loosened tooth or teeth; then, by binding tightly around the sound tooth and each of the loosened teeth the two lengths of the wire and crossing them in the dental interstices so as to form a kind of network, the sound and firm tooth of the opposite side will be reached, and this too must be wound around in a mesh, as it were, of the said network. Then, turning back, the same operation must be repeated, but inversely, until the point of departure is reached. All this must be done with much skill, so as to render the loose teeth completely unmovable. When the wire is tied, this must be done near the dental roots, so that the knot may not get untied; then with a pair of scissors the remaining part must be cut off and its two ends joined and twisted with a pair of pincers, hiding them between the sound tooth and the neighboring loose one. Such a ligature should remain in place during a whole lifetime; and in case it should come undone or the wire should break, it will be necessary to renew the operation. The following figure represents the ligature described: [Illustration: FIG. 54 Ligation for steadying teeth in cases of blow or fall (Abulcasis).] “Sometimes, when one or two teeth have fallen out, they are replaced in the sockets and bound in the aforesaid manner and remain there. The operation must be carried out with great delicacy and ability, by skilful hands.” As may be seen from the above quotation, in the days of Abulcasis replanting was already performed, although it is probable that the ligature was then left permanently. The author says, next, that the vacancy left by fallen teeth can be filled up with artificial ones, made of ox bone, they also being fixed in the manner above described; and he adds that they will be found not only of advantage from the esthetic but also from the functional point of view. Speaking of the cure of the ranula,[221] Abulcasis says that when the tumor, examined by the clear light of the sun, appears brown or black, hard and insensible, it is not to be operated, it being then of a cancerous nature. If, instead, it is whitish and full of liquid, it must be seized with a hook, and by means of a fine scalpel extirpated. The hemorrhage must be combated with powdered blue vitriol. After the operation mouth washes must be used of vinegar and salt.