A simple, efficient and easily made instrument which assists greatly in obtaining serum from the primary syphilitic lesion for dark field examination is pictured in the accompanying illustration. It consists of an ordinary all glass syringe of either 2, 5 or 10 cubic centimeter capacity, from which the tip and lowermost portion of the barrel are removed. This removal is accomplished by holding the tip of the syringe at a right angle against the side of a revolving emery wheel, and moistening the surface in contact with the wheel occasionally to diminish heating and insure a finer finish. Different sized instruments are advisable for use on lesions of varying magnitude.
When the instrument is to be used, the suspected lesion is cleansed in the customary manner and the open end of the instrument placed over the ulcerated area, surrounding it like an inverted cup. Slow withdrawal of the piston results