TECHNIQUE OF PUNCTURES 75 



the practice of the author for vein puncture, in making 

 a blood culture, to have the arm at the bend of the 

 elbow inside (sometimes the leg is used) scrubbed with 

 soap and water, using a very soft brush, washed with 

 sterile water, alcohol, ether, and a wet dressing of 

 1 to 5000 bichloride of mercury applied. This remains 

 for two or three hours, and when ready to do the 

 operation, a goodly quantity of sterile water, or 

 preferably, salt solution, is doused or sopped on the 

 skin. The purpose of this sterilization of the skin 

 for a long time by the wet dressing is to destroy 

 the bacteria always present in the deeper layers. They 

 are chiefly small white cocci not unlike the cocci that 

 cause abscesses. They will be considered later under 

 the name Staphylococcus epidermidis albus. 



There is little to be done by the nurse aside from 

 preparation and general assistance, but she should 

 know what is being done and why. 



Fluids are removed from the pleural cavity or 

 spinal canal and elsewhere because in these locations 

 bacteria of specific kind or in characteristic conditions 

 are to be found. For instance, in spotted fever (cere- 

 brospinal meningitis) the causative germs are found 

 within the pus cells as double, biscuit-shaped cocci, 

 and they have a particular staining reaction by which 

 they are recognized (see Chapter VIII). 



The blood is taken from the veins and grown in 

 broth alone or broth stiffened with gelatin or agar- 

 agar in order to find out if living bacteria are circu- 

 lating in the blood stream, as is the case in typhoid 

 fever and septicemia. 



For entering these cavities or veins a syringe, prefer- 



