70 PHLEBOTOMY. 



first effort, one should select an undamaged portion of the 

 skin for a second attempt so that the opening into the vein 

 ma}' be direct and clean. When the vein is opened lay the 

 instrument aside, the compression of the vein being contin- 

 ued in order to prevent aspiration of air into it and also that 

 the lips of the wound shall not become overlapped by which 

 the escape of blood would be impeded or stopped. The flow 

 of blood may be favored by inducing masticatory movements 

 by the animal. The amount of blood withdrawn varies be- 

 tween 3 and 8 liters, according to the size of the animal and 

 the object to be attained. The wound may be closed by an 

 interrupted or a pinned suture. For the latter, relieve the 

 compression on the vein and grasp the lips of the skin wound 

 between the finger and thumb and stick the pin perpendicu- 

 larly through the middle of it a few mm. from its borders. 

 Apply a noose of silk ligature previously prepared over the 

 pin and close and tie the loop. In applying the pin and 

 loop, take care not to elevate the skin from the underlying 

 part, which tends to the production of a hematonie. 



b. With the lancet the operation is preferably performed 

 on the right side of the neck. Compress the vein as illus- 

 trated in Fig. 3, and hold the lancet between the thumb and 

 index finger with the blade at right angles to the handle, 

 the thumb and finger being so placed on the blade that it 

 can barely penetrate the vein, and then push it in quickly 

 just in front of the compressing thumb through the skin, 

 subcutem and venous wall as deep as the fingers holding the 

 lancet will permit. 



Hold the blade perpendicular to the long axis of the 

 vein, and avoid directing the point dorsalwards, which would 

 endanger the superior wall of the vessel or cause the 

 lancet to glide over the wall and not enter the vein. When 

 the lancet has entered the vein extend the wound somewhat 

 toward the head by flexing the hand dorsally. In cattle it 

 is necessary to compress tte vein by means of a cord tightly 



