Even though one have a syringe capable of holding enough for several operations it is well to have a second at hand ready for use as the instruments sometimes break or spring a leak when least expected. Never use a syringe which leaks, as one cannot tell how much is going into the tissues and how much is escaping. Leaks invariably occur at the side of the needle base or at the point of juncture of the barrel of the instrument with its anterior portion. Paraffin in the solid state will seldom if ever escape along the side of the plunger within the barrel of the instrument when the all metal paraffin syringe is used and the all metal syringe is the only instrument which should be used for paraffin injections. The screw piston is preferable to the sliding piston under all circumstances as it gives the operator a better control over the injection. Injections are made with the paraffin compounds cold so that considerable pressure must be brought to bear to cause the harder mixtures to flow through a long needle. PREPARATION OF THE SYRINGE. The plunger should be removed from the syringe and the instrument in two parts should be thoroughly boiled before filling. It should be scrubbed with soap and water if dirty or corroded before it is dropped into the boiling water. After boiling for a half hour the barrel of the syringe which is closed anteriorly, except for the needle opening, is held up and the melted paraffin poured in until the instrument is quite full, then the plunger is fitted in and pressed down until it is possible to assemble the instrument ready for use. Needles should be boiled. Leather washers when not in use should be kept in solutions of alcohol. Preparations for operation, such as sterilizing syringe and needles should be done hours before operation. If the sterilized loaded syringe is placed in a sterile towel it may be kept for days and then before use to insure sterilization it should be soaked in a seventy per cent solution of alcohol. If a needle is attached to the syringe when it is thrown in the alcohol solution it will be found that the paraffin in the syringe will not be affected by the alcohol. The instrument may be used from the alcohol without even drying it. Before inserting the needle for the injection of the paraffin start its flow and observe that the paraffin is escaping from the needle in a perfectly smooth string. The same words as to preparation apply when the white vaseline is used. This agent should always be sterilized by heat before placing it in the syringe and when syringe and vaseline are sterile the exterior of the instrument may be re-sterilized at the time of using by alcohol soaking.