EXAMINATION BY CULTURAL METHODS 



197 



the vein, which may slip iin front of the needle if the intraven- 

 ous 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 withdraw the needle first 

 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 : Ex- 

 pel 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 Hos- 

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

 tubing- 4|- inches in length, and J' inch in 

 diameter, is drawn out to a tap-ered end, and 

 ground to fit the cap of a rather fine hypo- 

 dermic 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. 34). 



"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 

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



FIG. 34. PIPETTE 

 FOR COLLECTION 

 OF BLOOD FOR 

 BACTERIOLOGICAL 

 EXAMINATION. 



