230 INFECTIOUS AND PARASITIC DISEASES. 



In suspected diphtheria, for the purpose 

 Diphtheritic of diagnosis, and after recovery from diph- 

 CuLTUREs. theria, before raising the quarantine, to 



determine the presence or absence of the 

 specific bacillus, it is compulsory in many cities that a 

 specimen be taken from the patient's throat and sent to 

 the municipal laboratory for examination. For this pur- 

 pose a special outfit is furnished consisting of two glass 

 tubes, one, containing a sterile swab, the other, a cream 

 or chocolate colored jelly which fills about one- third of 

 the tube. The material in the second tube is blood- 

 serum which has been solidified in a slanting position 

 by heat. To make a culture, the swab is first smeared 

 over the affected area in the throat, and then immediately 

 applied to the slanting surface of the blood-serum. The 

 tubes are then returned to the laboratory where the one 

 containing the blood-serum is placed in a warm oven 

 (37.5° C. — 98.6° F.) for from twelve to eighteen hours. 

 A stained preparation of the bacteria, which by this 

 time have developed upon the blood-serum, is now ex- 

 amined with a microscope, and the presence or absence 

 of diphtheria bacilli determined. The following di- 

 rections, taken from the literature of the Philadelphia 

 Health Department, is an illustration of the instruc- 

 tions which accompany the tubes: 



DIRECTIONS FOR MAKING CULTURES. 

 "The patient should be placed in a good light, and, 

 if a child, properly held. In cases where it is possible 



