Venous blood is removed from the right side of the heart directly or indirectly, and the veins, only when it is deemed necessary by the operator. There are two methods of removing this arterial or venous blood from the body. These two methods are aspiration and drainage. Besides these two methods some modified methods or combinations of the two, are given. Aspiration consists in actually pumping the blood from the heart, arteries or veins. In this method, if blood is to be taken from the heart directly, the trocar is used; if the blood is to be taken from the heart indirectly or from the arteries or the veins one of the drainage tubes is used. Either the trocar or the drainage tube is connected by rubber tubing, to the goose neck on the blood bottle, which in turn is connected by rubber tubing to the aspirator side of the aspirator and injector pump. When the air is drawn from the blood bottle, there is a vacuum formed, which will aspirate or draw the blood from the heart directly or indirectly from the arteries or veins. The one great disadvantage of this method is that if the vacuum is made too great, the artery or vein will collapse ahead of the drainage tube and thus prevent the successful aspiration of the blood. Drainage or gravity consists in opening one of the principle arteries or veins of the body, inserting a blood drainage tube into the artery or vein as far as it seems practical, and then connecting the blood drainage tube to the blood bottle by means of rubber tubing. The blood bottle should be placed considerably lower than the body in order to have the blood drain successfully. If the femoral artery or vein is used, the body ought to be on a considerable incline, the head at least one foot higher than the feet in order to get the maximum amount of blood. If the axillary, brachial, or carotid, or their corresponding veins are used, the body ought to be on a level or turned to the side of the opening veins. Simple drainage in itself is not a very successful method of getting the maximum amount of blood from the body. The process can be modified in three ways which are as follows: (1) By placing the blood drainage tube in the vein and the arterial tube in the corresponding artery. Inject fluid into the arteries which will tend to push the blood in turn from the capillaries into the veins, and out into the drainage tube into the blood bottle. This modified method has been called by Robbins “Displacement.” This is a good name and one which should be generally adopted. (2) By placing the blood drainage tube in the artery or vein, preferably the femoral, and connect it by means of rubber tubing to the blood bottle. The operator now stands at the head of the subject, he reaches over, takes hold of each hand of the subject, raises the arms of the subject to right angles with the subject, then crosses the arms and with a steady gentle pressure bears down on the chest of the subject over the heart region.