Curved needles, used by some operators, are never needed, and the author does not see how they could be applied at any time in preference to the straight. As much of the paraffin mixture can be forced out of the syringe as may be desired by screwing the piston down into the barrel. The piston rod may be graduated in five- or ten-drop divisions, but the operator rarely ever refers to the scale. He judges the amount required by the elevation of the tissues brought about by the presence of the paraffin thus forced under the tissue. Experience soon teaches him the amounts necessary or judicious in each case, always remembering that it is better to do a second and later injection than to hyperinject. The entire instrument being of metal permits it to be sterilized as readily and in the same manner as any other metallic instrument. It is understood that the syringe must be taken apart for sterilization at all times. Lubrication, to facilitate operation, is never required, since the nature of the mixture used in the syringe answers this purpose in every way. Owing to the greater amount of metal in the solid piston itself, the latter is very likely to expand under dry heat sterilization or boiling, so much so that for a moment it cannot be introduced within the barrel. This can be quickly overcome by dipping it into cold sterile water or absolute alcohol, which brings about its contraction. After using, the syringe should be emptied entirely, unscrewed and sterilized, and placed in the metal case furnished for it. A screw cap is furnished to take the place of the needle when not in use. The method of filling and using the syringe will be considered later. PREPARATION OF THE SITE OF OPERATION The same surgical precautions should be observed when a paraffin injection is to be undertaken, as with a minor surgical operation. It is hardly found necessary to prepare the site of operation the day before, nor need the patient be detained for such time for the purpose of making him ready. With careful observance of ordinary surgical technique, both as to surgeon and patient, all of this class of operations can be performed in any physician’s office, providing that both instruments and the mass to be injected have been rendered sterile. Especial care should be given to the operator’s hands, for with these he not only handles the instruments, but must also mold the mass injected, thus frequently coming in contact with the needle opening or openings made in the skin. When injections are to be made in the cheeks of the patient, the mouth should be prepared by cleansing the teeth thoroughly and washing out the buccal cavity with warm boric acid or hydrogen peroxid solution, or any of the preparations of the Listerine composition. This rinsing should be continued every few minutes for at least ten minutes before the operation is undertaken.