ABSTRACTS 129 



the serum dialyzed and tested. In the first place, each serum after 

 having been combined with its specific bacterial substrate, reacted 

 positively, the other combinations being negative. In the second place, 

 each substrate that had already been so combined with its specific 

 serum, upon being subsequently combined with the non-specific sera, 

 acted on all of them so as to yield a positive reaction upon dialysis, 

 thus demonstrating that this phase of the reaction is due to autodigestion 

 of the serum and is non-specific. Whether the sensitization of the sub- 

 strate corresponds with the usual antigen-antibody reaction is a point 

 left for further study.— P. B. H. 



LABORATORY TECHNIQUE 



On a Colorimetric Method of Adjusting Bacteriological Culture Media to 



any Optimum Hydrogen ion Concentration. S. H. Hurwitz, K. F. 



Meyer and Z. Ostenberg. Proc. Soc. Exp. Biol, and Med., 1915, 



IS, 24-26. 



The indicator is phenolsulphonephthalein 0.01 per cent. The final 

 adjustment is made after sterilization of the medium, with aseptic 

 technic, the readings being made in a specially devised comparator 

 against a standard color solution. — W. J. M. 



The Use of Brilliant Green for the Isolation of Typhoid and Paratyphoid 

 Bacilli from Feces. Charles Krumwiede, Jr., Josephine S. Pratt 

 AND Helen I. McWilliams. Jour. Infect. Diseases, 1916, 18, 1-13. 

 The success of the authors and others in the use of brilliant green 

 broth for the enrichment of typhoid and paratyphoid bacilli in feces 

 led to the attempt to produce a dye agar. After many trials a 

 medium of the following constitution was found to be satisfactory. 

 Extract of beef (Liebig's) 3 gm., Witte's peptone 10 gm., salt 5 gm., 

 agar 15 gm., water 1000 cc. Dissolve in autoclave; the final reaction is 

 set to the Andrade indicator, adding 1 cc. to a 100 cc. bottle of agar; the 

 reaction may be set at time of preparation or (preferably) when used. 

 If the latter, after dissolving, render slightly alkaline to litmus, bottle in 

 100 cc. amounts and autoclave. Just before use, adjust 0.6 to 0.7 per 

 cent to phenolphthalein (hot titration) then add to each 100 cc. 1 per 

 cent lactose and 0.1 of glucose (25 per cent sterile solutions) and finally 

 the appropriate amount (0.2, 0.3 or 0.4 cc.) of a 0.1 per cent solution of 

 brilliant green. Use about 16 cc. of agar for each plate, allowing them to 

 stand open until agar has cooled. Inoculate as in Endo plates. The 

 method of use is as follows: Rub up in extract broth a large sample of 

 feces (1: 15 by volume.) Place one loop of suspension on a 0.2 cc. and 

 on a 0.3 cc. plate; streak in order given and then on an Endo plate. 

 Place two loops on each of a similar pair of green dye plates; streak in 

 same order and then on Endo plate. Use a heavy platinum wire looped 

 at end. For a direct agglutination test a macroscopic slide method is 

 employed. For fishing, the Russell medium, with 1 per cent Andrade 

 indicator substituted for litmus is employed. As an added precaution 



