<>! MATERIAL FOR I-XAM I \ ATION 139 



add 5 c.c. We have made by^this mixture of blood and bouillon a 

 most suitable medium for the growth of all bacteria which produce 

 septicaemia, and at the same time have added a sufficient quantity of 

 blood to ensure us the best possible chance of having added some of 

 the bacteria producing the disease. We also add to each several 

 tubes of melted nutrient agar, at 40 C., 1 c.c. of blood and pour into 

 Petri plates, so as to indicate roughly the number of organisms present 

 if they happen to be in abundance. From wounds, abscesses, cellulitis, 

 etc., the substance for bacteriological examination can, as a rule, best be 

 obtained by means of a syringe, or when opened , by small rods armed 

 with a little absorbent cotton. A number of these can be carried in a 

 test-tube. Both rods and tubes must be sterile. The swab is inserted 

 in (the wound, then streaked gently over the oblique surface of the 

 nutrient agar in one tube, over the blood serum in another, and then 

 inserted in the bouillon. Finally, either at the bedside or in the labo- 

 ratory, material is thinly streaked over the surface of nutrient agar 

 contained in several Petri dishes. We inoculate several varieties of 

 media, with the hope that one at least will prove a suitable soil for the 

 growth of the organisms present. From surface infections of mucous 

 membranes, as in the nose, throat, vagina, etc., the swab, again, is 

 probably the most useful instrument for obtaining the material for 

 examination. The greatest care, of course, must be used in all cases 

 to remove the material for study without contaminating it in any way 

 by other material which does not belong to it. Thus, for instance, 

 if we wish to obtain material from an abscess of the liver, where the 

 organ lies in a peritoneal cavity infected with bacteria, here one must 

 first absolutely sterilize the surface of the liver by pressing on it the 

 blade of a hot iron spatula before cutting into the abscess, so that we 

 may not attribute the infection which caused the abscess to the germs 

 which we obtained from the infected surface of the liver. From such 

 an organ as the uterus it is only with the greatest care that we can avoid 

 outside contamination, and only an expert bacteriologist familiar with 

 such material will be able to eliminate the vaginal from the uterine 

 bacteria. 



A statement of the conditions under which materials are obtained 

 should always accompany them when sent to the laboratory for exami- 

 nation, even if the examination is to be made by the one who made 

 the cultures. These facts should be noted, or otherwise at some future 

 date they may be forgotten and misleading 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 difficulties 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 immedi- 

 ately subjected to cultures or animal inoculations it should be trans- 

 ferred 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 



