560 The Philippine Journal of Science i«» 



whom had been in more or less intimate contact with the case of 

 clinical diphtheria reported; 232 children from 1 to 15 years 

 old, inmates of the Philippine Government Orphanage at San 

 Pedro Macati, near Manila, where no diphtheria has ever oc- 

 curred since the establishment of the institution in 1917; and 

 553 male and female adults of Bilibid Prison where diphtheria 

 has never been known to occur. 



One specimen was taken from each child and in cases where 

 the results were doubtful another specimen was obtained. With 

 the aid of a wooden tongue depressor, the tonsils and pharynx 

 were swabbed with a sterile cotton pledget attached at the end 

 of a small applicator stick. The swab was rubbed against the 

 tonsils and pharynx by revolving the stick in the fingers in 

 such a way as to bring the swab thoroughly in contact with 

 the tonsils and the lacunas or with any area at the pharynx 

 that looked suspicious. The infected swab was then inserted 

 into a Loeffler's serum tube and rubbed gently back and forth 

 over the entire surface of the serum, revolving the stick so as 

 to bring the swab in thorough contact with the serum, avoiding 

 at the same time any break in the surface of the slant; and 

 afterwards the swab was thrown away. 



The inoculated Loeffler's blood serum tubes were taken to the 

 laboratory and after incubation of from eighteen to twenty-four 

 hours at 37° C. the cultures were examined, and all suspicious 

 colonies (whitish, pearly, rather elevated) and the bottom of the 

 tube (when there was proteolysis of the serum) were examined 

 microscopically. The smears were stained with Loeffler's meth- 

 ylene blue, and the colonies showing suspicious bacilli were either 

 fished out with a fine platinum needle and transplanted to sev- 

 eral Loeffler's blood serum tubes in order to get discrete colonies, 

 or plated in glycerine agar in order to be able to get pure cul- 

 tures. In some cases one single colony was transplanted; in 

 other cases several colonies were transplanted, especially when 

 isolation was made by the glycerine agar plate method where the 

 colonies are so small and hard to pick out with the point of the 

 needle. In such cases a small area was marked out and examined 

 microscopically to determine uniformity of colonies; the area 

 was then rubbed over with a fine platinum loop and smeared on 

 Loeffler's blood serum. 



The morphology of the bacteria was studied in cultures from 

 eighteen to twenty-four hours old, in Loeffler's blood serum, and 

 stained with Loeffler's methylene blue, Neisser-Gin, and Gram's 



