WET CUPPING. 



have already been mentioned in connection with intravenous injections. 

 A simple, large, hollow needle is all that is required. Suction with a syringe 

 is superfluous. Only in Morgenroth's method of removing blood directly 

 from the heart of guinea-pigs is aspiration necessary. In rabbits enough 

 blood can be collected by making an incision into the vein along its long axis, 

 with a sharp knife, or by dividing the vein transversely with the scissors. 

 The blood thus collected is not absolutely sterile. 



In man, if only a small quantity of blood is required, it can be obtained 

 from the finger or ear. If, however, a larger amount is necessary, puncture 

 of one of the veins in the bend 

 of the elbow with the Strauss 

 canula is resorted to. It goes 

 without saying that this area 

 must be properly disinfected 

 with soap and water, ether, 

 alcohol or sublimate. Wright's 

 method for collecting moderate 

 quantities of blood will be re- 

 viewed in the chapter on opsonic 

 studies. 



If the vein is prominent, the 

 canula is thrust into the vein 

 directly through the skin. Here 

 the author has found it more 

 convenient to point the canula 

 upward, i.e., in the direction of 

 the blood stream. 1 In cases 

 where the vein does not stand 

 out it can be made to do so 

 either by applying pressure with 

 the finger upon its central part or placing a tight rubber bandage or rubber 

 tube about the arm. This should not, however, be tight enough to obliterate 

 the radial pulse. In very fat individuals, even these means do not suffice 

 so that the vein must be dissected free and incised. After completion of the 

 venesection the arm is elevated, slight pressure made upon the wound with 

 sterile cotton and a bandage applied. If a small amount of blood is sufficient, 

 and, as in most serological examinations absolute sterility 



is not essential, venesection can be replaced by the method 

 Wet-cupping. p 



of wet-cupping. For this procedure a scarifier and Bier cup 



are required. The technique is as follows (Fig. 7). 



FIG. 6. Puncture of vein. (Original.} 



1 The editor has found that more blood is obtained by thrusting the canula into the vein in 

 the reverse direction. 



