Paraffin in the liquid state may be drawn from a large container directly into the syringe when the needle has been removed. The needle may then be screwed in place and the instrument held with the point of the needle directly upward and pressure made upon the piston until all air escapes and the liquid paraffin begins to flow. Then the instrument may be allowed to cool and its contents to consolidate. Material injected at room temperature. All these injections are made with the material in the syringe at room temperature. The syringe may be left filled for days and not heated at all when the injections are finally made. In mid-winter if the syringe has been kept in a cold room its temperature may be so low that it may be advisable to warm it somewhat, but at an average temperature of seventy degrees Fahrenheit the mixture first described should flow freely through an ordinary hypodermic needle. PREPARATION OF THE PARAFFIN. Some operators have said a good deal about the paraffin and the proper place to secure it. As nearly as can be learned the compounds used in this country are products of the Standard Oil Company. The paraffin used in the formulae of this book has an average melting point of 130. For reducing the melting point of the paraffin mix the paraffin with the white vaseline of the Chesborough company. If an agent is sold in a tin stamped white vaseline it should have the name on the tin of the Chesborough company as this is the only firm having the right to use this name. Petrolatum albi or white petrolatum is a few cents cheaper than the vaseline but the difference is of so small an amount that it is better to use the vaseline rather than packages which may vary more than the Chesborough product. FORMULA NUMBER ONE. White vaseline, one-half pound. Paraffin, one-half pound. Melt together. This should be sterilized by having the mixture stand in a covered container in a vessel of water which is also covered and the water should be kept boiling for a half hour. Containers for sterilized compounds.