The syringe at that time consisted of a glass barrel, of a size to hold 6 c.c. of liquefied paraffin. At either end of the barrel tube were placed metal ends, the distal one containing a cap with a screw thread to receive the needle, the upper cap being threaded to receive a check nut through its center and on its outer surface, on opposite sides to each other, two metallic rings to accommodate the thumb and forefinger. The center of the check nut was double threaded to receive the piston rod, the piston or plunger being held in place by two, upper and lower, washer nuts, the lower being threaded to receive a small rod passing through the bored-out center of the piston rod, and which ended in a check nut, in the handle, threaded upon the outer or manual end of the piston rod, in such a way that the fiber or asbestos piston washer could be tightened and loosened at will. The syringe permitted of being used as an ordinary syringe by unscrewing the cap check nut or be made into a screw drop syringe by screwing the same nut into place. By turning the handle end of the piston rod the contents of the syringe were forced out smoothly and evenly in any quantity desired. With the later employment of the cold, semisolid preparation of vaselin and paraffin, as heretofore considered, it was found necessary to reënforce this syringe, so that the greater pressure necessary to eliminate the wormlike thread of hydrocarbon would not force off the lower cap or break the barrel of the syringe at its needle end. This was done for the author by the Kny-Scheerer Company, December 6, 1902, when metallic strips were added to opposite sides of the glass barrel connecting the lower with the upper cap. The instrument as then made is shown in Fig. 289. [Illustration: FIG. 289.—AUTHOR’S DROP SYRINGE.] At the same time the same firm made the author a syringe entirely of metal, similar in construction, except that the barrel was made larger in diameter and shorter in proportion to bring the instrument near to the seat of operation. The regulating washer rod was not needed, since in this instrument no washers were required, the piston head being made of solid metal throughout and the rod being soldered to the plunger, thus overcoming any objectionable fault in sterilization. This type of syringe was found to be most suitable for the cold, semisolid injections, and is of the type now universally used except for the slight modifications of the various operators. It is illustrated in Fig. 290. [Illustration: FIG. 290.—AUTHOR’S ALL-METAL DROP SYRINGE.]