MATERIAL FOR EXAMINA TION IN DISEASE. 243 



A statement of the conditions under which materials 

 are obtained should always accompany them when sent 

 to the laboratory for examination, even if the exami- 

 nation is to be made by the one who made the cul- 

 tures. These facts should be noted, or otherwise at 

 some future date they may be forgotten and mislead- 

 ing information sent out. The work of obtaining 

 material for examination without contamination is at 

 times one of extreme difficulty. It simply must be 

 remembered that if contamination does take place our 

 results may become entirely vitiated, and if the diffi- 

 culties are so great that we cannot avoid it, it may 

 simply mean that under such conditions no suitable 

 examination can be made. Where the substance to 

 be studied cannot be immediately subjected to cultures 

 or animal inoculations, it should be transferred in a 

 sterile bottle as soon as possible to a location where the 

 cultures can be made. If for any reason delay must 

 take place, the material should at least be put in a 

 refrigerator, where cold will both prevent any further 

 growth of some varieties of bacteria and lessen the 

 danger of the death of others. After having made 

 the cultures, some of the infected material should 

 always be smeared on a couple of clean slides or cover- 

 glasses and allowed to dry. These can be stained and 

 examined later, and may give much valuable informa- 

 tion. 



In obtaining samples of fluid, such as urine, feces, 

 etc., the bottles in which they are placed should always 

 be sterile, and, of course, no antiseptic should be added. 

 It is necessary to clearly explain this to the nurse, for 

 she has probably been instructed to add disinfectants 

 to all discharges. Disinfected material is, of course, 



