146 CLINICAL BACTERIOLOGY ANf H^MATOLOG"? 



pressure is low or the instrument blunt. In this case the vein 



may be made tenser by gently massaging blood in it towards the 



bandage and retaining it there by a finger pressed on to the vessel. 



As soon as the requisite amount of blood has been obtained, 



remove the bandage from the upper arm, and 



then withdraw the needle ; if you leave it on 



longer there may be a considerable amount 



of haemorrhage into the tissues, which does 



no harm, but leaves an unsightly bruise. 



Next make the cultures as follows : Expel 

 nearly all the blood into one of the broth 

 tubes and shake gently, and then put about 

 I c.c. into the agar tube, and place the latter 

 in an inclined position, so that the blood will 

 clot in an even film over the surface. 



Seal the puncture in the skin with col- 

 lodion. If there is haemorrhage into the 

 tissues, bandage the forearm evenly from 

 below upwards. 



Undoubtedly the simplest and best of all 

 methods is that described by James and 

 Tuttle {Report of the Presbyterian Hospital, 

 New York, 1898). " A piece of glass tubing 

 4J inches in length, and ^ inch in diameter, is 

 drawn out to a tapered end, and ground to fit 

 the cap of a rather fine hypodermic needle. 

 The larger end of the tube having been 

 stopped with a cotton plug, the whole is then 

 placed in a larger tube, and both ends of this 

 are similarly plugged with cotton* (Fig. 35). 

 " The apparatus is then sterilized 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 

 * These may be obtained from F. Ash, Edmund Street, Birmingham. 



w 





Fig. 35. — Pipette 

 FOR Collection 

 OF Blood for 

 Bacteriological 

 Examination. 



