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 
ic.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 hemorrhage 
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 
