COLLECTION OF BLOOD. 179 



" The apparatus is then sterilised by dry heat. In 

 using it the inner tube with needle attached is removed ; 

 the skin over one of the most prominent veins of the 

 anterior surface of the forearm, near the bend of the 

 elbow is selected, a piece of rubber tubing or a few 

 turns of a bandage being passed round the arm above 

 with moderate pressure, in order to produce distension 

 of vessels. The needle is then plunged into the vessel 

 and generally blood begins to flow by the blood-pressure 

 itself, but any quantity desired may be obtained by 

 making gentle suction either by applying the mouth 

 directly to the end of the tube where it is stopped with 

 cotton, or through the medium of a small piece of rubber 

 tubing slipped over it. 



" By the above instrument vein punctures have been 

 made in about 150 cases of a variety of diseases. At 

 no time was any difficulty experienced in obtaining the 

 amount of blood desired, which was generally about 

 i c.c. In a few instances it was necessary to try two 

 punctures before securing a free flow through the 

 needle ; in no case was there any local reaction what- 

 ever at the seat of puncture, nor did the patient 

 complain of pain and annoyance." 



The following points are worthy of attention : Select 

 for the puncture a vein which is superficial (as shown by 

 the blue colour appearing through the skin) not merely 

 prominent, for a deep vein will often slip in front of the 

 needle. Insert the needle very obliquely, with the point 

 directed away from the body. Lastly, remove the ban- 

 dage as soon as possible after withdrawing the needle, 

 or there may be a considerable amount of haemorrhage 

 into the subcutaneous tissues. If this should happen 

 place a pad of lint over the puncture and bandage the 

 arm from the wrist upward. No harm will result. 



N 2 



