METHODS OF INOCULATION 753 



Manufacturing concerns market their products in syringes all ready 

 for injection. When injecting tetanus antitoxin, it is necessary to 

 empty the syringe into another sterile syringe, as shown in the accompany- 

 ing illustration (Fig. 143), which will fit an appropriate needle. Since 

 the plunger of the purchased syringe oftentimes adheres to the barrel 

 and renders the injection jerky and difficult, I frequently transfer the 

 serum to a sterile, all-glass syringe which I know will work smoothly and 

 satisfactorily. 



TW 



FIG. 143. INTRASPINAL INJECTION BY MEANS OF A SYRINGE. 

 The line indicates the crest of the ilium, and usually passes between the third 

 and fourth lumbar vertebrae, which is the proper point for inserting the needle. The 

 site of injection has been painted with tincture of iodin after cleansing with soap, 

 hot water, and alcohol. An assistant holds the patient to prevent sudden jerking 

 and possible accident. 



2. Lumbar puncture is performed as for the gravity method while 

 blood-pressure observations are being made. When sufficient fluid has 

 been removed, the loaded syringe is- attached to the needle and the in- 

 jection slowly given. The physician is frequently tempted to inject 

 the serum and complete the operation quickly, but it is better to inject 

 it in amounts of 0.5 to 1 c.c. every half to one minute, being guided by 

 the blood-pressure readings and general condition of the patient. If 

 the pressure falls below 20 mm. of mercury or other symptoms of col- 



