I04 BACTERIOLOGY 



the body, from instruments or from the air during the collection 

 and transportation to the laboratory. Unfortunately the lab- 

 oratory study of such material is too often rendered difficult, un- 

 trustworthy or even worthless through lack of attention to this 

 point. 



When merely microscopic examination is to be undertaken, 

 contamination may not be serious, and an antiseptic, such as 

 two per cent of carbolic acid, may be added to the material, if 

 fluid, and if solid it may be immersed in ten per cent formalin. 

 The bottles used should be new and clean. Such material may 

 also be spread on microscopic slides or cover-glasses in a thin 

 layer, dried, fixed in the flame, and transported to the laboratory. 

 This method is not always free from danger when the material 

 passes through several hands. Special precautions for collecting 

 material for microscopic examination will be considered in discuss- 

 ing the specific pathogenic microbes. 



Specimens of sputum should be raised from the trachea, bron- 

 chi and lungs after previously cleansing the mouth. Sputum 

 should be received into a sterile wide-mouthed bottle, and stop- 

 pered with a sterilized cork. The exterior of the bottle should 

 then be carefully washed with 5 per cent carbolic acid. 



Urine should be collected by catheter with careful aseptic 

 tec-hnic, and should be received in a clean sterilized bottle. When 

 the passage of a catheter is deemed unwise, the urine should be 

 received directly into a sterile bottle after surgical cleansing of 

 the urinary meatus and must be examined in the laboratory with- * 

 out delay, contamination being assumed to have taken place. 



Blood and transudates are collected by the technic previously 

 described (page 97). Blood is drawn from the vein by means 

 of the Luer syringe and is quickly ejected into several flasks of 

 broth (150 to 250 c.c.) and into Petri dishes where it is mixed with 

 melted agar (cooled to 50° C.) before clotting takes place. 



A most convenient tube for collecting blood has been described 

 by Taylor.i The side arm (Fig. 39) is accurately ground at the 



' Taylor, R. M.: Proc. N. Y. Path. Soc, 1914, 14, p. 37. 



