172 APPLIED BACTERIOLOGY FOR NURSES 



water from a faucet care should be taken to secure a 

 typic specimen by allowing the water to run for some 

 time before collecting. In the case of springs, w^ells, 

 reservoirs, etc., one should not dip water from the 

 surface, for such a specimen would probably contain an 

 undue proportion of bacteria from the dust of the air. 



Milk.^When milk is to be examined, one must be sure 

 to secure a representative sample by thoroughly mixing 

 milk and cream. The latter always contains a very 

 large number of bacteria. 



Autopsies. — Specimens of organs are secured free from 

 outside contamination by first searing the surface of the 

 organ with a hot iron, and then cutting a piece of tissue 

 from beneath the seared surface. Similarly, in secur- 

 ing specimens of heart's blood the surface of the heart is 

 first seared with a hot iron, and then, with a sterile hollow 

 needle, blood is draw^n from within the heart cavity by 

 thrusting the needle through the seared surface. The 

 piece of tissue or blood should be placed in a sterile 

 bottle or test-tube plugged with cotton and at once 

 carried to the laboratory. 



Urine. — The nurse will be familiar with the collection of 

 specimens of urine for the ordinary chemical and micro- 

 scopic examination. In certain instances, however, it is 

 desired to make cultures, and then great care must be 

 taken to collect the specimens, by means of a sterile cath- 

 eter, in a sterile bottle. 



Feces. — Bacteriologic examinations of feces are fre- 

 quently undertaken in order to discover the presence of 

 typhoid bacilli. Such specimens should be placed in a 

 clean wide-mouthed bottle and tightly corked. The 

 bottle should never be more than half-full. The specimen 



