WILLIAM PALMAR LUCAS, M. D v AND HAROLD L. AMOSS, M. D. 245 



plates were made, using varying amounts of the emulsion ac- 

 cording to the character of the stool and the strength of the 

 emulsion, with bent glass rods on Endo's medium and incubated 

 for 18 hours. On these plates B. dysenteriae appear as slightly 

 elevated, clear, colorless colonies measuring in diameter from 

 .5 mm. to 1.5 mm., according to the total number of colonies on 

 the plate. All suspicious colonies were fished into litmus- man- 

 nite-semisolid media and incubated 18 to 24 hours. If at this 

 time there was growth characteristic of the Flexner or Shiga 

 type of B. dysenteriae a tube of plain broth (reaction-h.5) and a 

 tube of litmus milk were inoculated with the culture and incu- 

 bated for a day. If at the end of this time the litmus milk 

 showed the characteristic lilac color microscopic agglutination 

 of the broth culture at a dilution of 1-200 was made. Later in 

 these investigations, in order to make a diagnosis more quickly 

 and for the reason that a large number of specimens were being 

 studied, suspicious colonies from the plates were fished directly 

 into plain broth (made from meat extract reaction+.5) and incu- 

 bated for about 18 hours, when a drop of agglutinating horse 

 serum was added to the tube. First, Flexner serum was used 

 and then if in three or four hours there was no agglutination, 

 a drop of Shiga anti-dysenteric serum was added. If either 

 agglutination was positive the supernatant broth was drawn off 

 and sterile bouillon was added to the tube, the tube shaken and 

 a loopful transferred to another tube of broth and plates made 

 from this. After incubation the colonies were fished and carried 

 through mannite, semisolid, litmus milk and the agglutination 

 test made a second time. The strains were finally transferred 

 to agar slants for preservation. By this method a tentative 

 diagnosis was reached in about 36 hours. It was found that a 

 positive microscopic agglutination could be allowed to stand for 

 several hours and the agglutinated organisms would grow when 

 transferred to fresh broth. Of the 33 cases that were studied 

 culturally, six cases proved already to have the dysentery organ- 

 ism. Five of them had the Flexner type of the dysentery organ- 

 ism and one the Shiga. Two of these cases received three vac- 

 cinations, as follows: The first vaccination consisting of 1 c. c. 

 of anti-serum and ^ c. c. of the standard emulsion, 50,000,000 

 bacilli, on the second inoculation they received simply 50,000,000 

 bacilli ; no anti-serum ; on the third inoculation they received 

 100,000,000 bacilli, or 1 c. c. of the standard emulsion. Three 

 of the cases received only two injections, the first with anti- 

 serum and the second without. One case received only one 

 injection of anti-serum and vaccine. In none of these cases was 

 the dysentery organism suspected before the vaccine was given, 

 as it was the intention at first to avoid giving any case having 



