DIPHTHERIA. 153 



its ends, and on which a little absorbent cotton is twisted. 

 The test-tube containing the swab is plugged with absorbent 

 cotton and then thoroughly sterilized by dry heat for one 

 hour at 1 50 C. The blood-serum and swab are neatly 

 packed together in a small pasteboard or wooden box, to- 

 gether with a blank form giving instructions as to how to 

 make the cultures. 



The cultures from the throat are made as follows : 



The patient is put in the best possible light, and if he is a 

 child is held firmly by an assistant, the mouth is opened, the 

 tongue depressed by means of a spoon or other instrument, 

 the swab taken out of its containing tube and gently rubbed 

 over the false membrane or exudate in the throat, if any, 

 or if no false membrane be present, over the surface of the 

 pillar of the fauces, after which, without laying down the 

 swab, the serum-tube is taken, the plug of cotton removed, 

 and the surface of the swab which has been in contact with 

 the throat of the patient is gently and freely rubbed over the 

 surface of the blood-serum, being careful not to break into it, 

 and certain to rub all sides of the swab upon the serum. 

 After which the swab is returned to its tube, both tubes 

 plugged, and the whole outfit with the blank form filled in is 

 returned to the laboratory. On receiving the tube at the 

 laboratory it is incubated at a temperature of 37 C. for 

 twelve hours, at the end of which time it is ready for exami- 

 nation. If the case is one of diphtheria, the typical diph- 

 theria growth is found on the surface of the culture. This 

 consists of grayish or yellowish-white glistening spots, and a 

 cover-glass preparation made of these shows in typical cases 

 the Klebs-Loeffler bacillus, as short, thick rods, with rounded 

 edges, irregular in shape, showing a decided staining in some 

 parts of their body, deficient in color in other parts, and 

 characterized chiefly by the variety of form of the different 

 bacteria forming the culture. 



In exceptional cases it is possible to find colonies as early 

 as five or six hours after incubation. 



Indeed, in very many cases, in the municipal laboratory in 



