congestion is then released, and at the same time the tube and cannula, held at the lower end with the right hand in such manner that the index finger is free, is withdrawn from the vein. At the moment of withdrawal the end of the cannula is closed with the right index finger. To prevent hæmorrhage from the donor’s vein, a ligature previously put round it is tied by an assistant, or pressure on it is maintained with a sterile swab. The operator must now, without a moment’s delay, carry the tube filled with blood over to the recipient. An opening in his vein is made by an assistant in the same manner as already described, the finger is removed from the cannula, and its point is instantly introduced into the vein. It is now necessary to produce some degree of positive pressure in the tube to ensure that the blood shall at once begin to flow steadily into the vein. This is done with a rubber bellows, attached by an assistant to the upper side tube, and the level of the blood in the tube should at once begin to fall. Great care must be taken that the positive pressure is released before the tube is completely emptied of blood in order to avoid the obvious danger of the entry of air into the patient’s vein. When the tube is nearly empty it is withdrawn, the vein is ligatured, and the wounds in donor and recipient are sutured. The most convenient pattern of Kimpton-Brown tube holds only about 500 cc. of blood, so that if more is needed, the process must be repeated. There is virtually only one cause of failure in transfusion by this method, and that is the occurrence of clotting in the cannula or at the bottom of the tube. If it does occur at any stage of the operation, it cannot be remedied. It may happen when the tube is nearly full; if so, the blood that has been withdrawn cannot be used. Clotting may be due to an imperfection in the paraffin coating on the glass, but if there is any delay from any cause, it may take place independently of this. The method is therefore never absolutely certain of success even in the hands of an expert, and for general use it is certainly unsuitable. It was introduced into the British Army by some of the American surgeons in 1917, and was used by the writer under the guidance of Major Alton of the Harvard Medical Unit during the first battle of Cambrai with good results. Many of the English surgeons, however, soon abandoned it as a routine method in favour of anticoagulants. There are other objections to it besides its uncertainty. A vein must be exposed by dissection in both donor and recipient, so that avoidable injury is inflicted on the former. It is not a perfectly clean method, some blood necessarily escaping at each successive stage in the process, though an expert can reduce this to a minimum. In the hands of a novice it may occasion a very bloody scene. The whole operation is one of urgency, and the best interests of donor and recipient cannot always be considered.