SECRETIONS AND EXCRETIONS. 231 



to get a good view of the throat, depress the tongue and 

 rub the cotton swab gently, but freely, against any 

 visible exudate, revolving the wire between the fingers, 

 so as to bring all portions of the swab in contact with the 

 mucous membrane or exudate. In other cases, includ- 

 ing those in which the exudate is confined to the larynx, 

 pass the swab as far back as possible, avoiding the 

 tongue, and rub it freely as described above against the 

 mucous membrane of the pharynx and tonsils. With- 



FiG. 27. — Method of inoculating culture media. (WUliams.) 



draw the cotton plug from the culture tube, holding 

 it so that the portion withdrawn from the tube does not 

 come in contact with the fingers or with any other 

 substance. Insert the swab and rub it gently but 

 thoroughly back and forth over the entire surface of 

 the blood-serum. Do not allow the swab to touch 

 anything except the throat of the patient and the sur- 

 face of the serum. Do not push the swab into the 

 serum, nor break the surface in any way. Do not use 



