The lymph may be much longer preserved if hermetically sealed in _glass tubes_. These are about the thickness of a darning-needle, 3 inches long, and open at both ends. When the tube is to be charged, one end is inserted in the lymph exuding from a punctured vesicle; a drop then enters the tube by capillary attraction, but filling not more than half its interior: a few shakes of the hand will send the drop a little further in. The lymph end of the tube is then taken in the thumb and forefinger, while the unoccupied part of the tube is passed once or twice quickly through the flame of a candle. This rarifies the air, and while it is warm the end is closed by melting it at the edge of the flame. The second end is then closed in the same way as the first. When the lymph is wanted for use, the ends of the tube are broken, and the lymph blown out on the point of a lancet. Lymph preserved in these tubes retains its efficacy an indefinite time. The National Vaccine Institution, Russell Place, Fitzroy Square, London, W., supplies to medical practitioners both points and tubes gratis on application. In performing the operation the common lancet does very well; but two or three forms of narrow-grooved lancets are employed by surgeons for this purpose. The operation is most successful when the lymph is transferred direct from arm to arm; the lancet making the puncture is then charged at the vesicle of a child vaccinated a week before, and points are unnecessary. When making the puncture the surgeon grasps the child’s arm in his left hand, puts the skin on the stretch over the insertion of the deltoid with his left forefinger and thumb, pushes the lancet downwards between the cutis and cuticle, about 1-10th of an inch, to raise the latter in a little pocket; he then charges his lancet with lymph and inserts it in the pocket, or if using points, inserts the moistened point for a minute, taking care as he withdraws the point to press the skin down on the point with his left thumb, that the lymph may be well wiped off the point and left in the wound. This process is repeated four or five times and the operation is complete. The corium should not be penetrated, or it will bleed freely and the blood will wash away the lymph; one drop of blood is of little consequence; indeed, it shows that an absorbing surface has been reached.