114 SUMMARY OF CUERENT RESEARCHES RELATING TO 



patient's vein are added to 10 c.cm. of the medium, which is then 

 incubated in the usual way. In every case where positive results were 

 obtained in bile culture, comparable results were forthcoming in the 

 citrated broth cultures, the only drawback to the procedure being that 

 there was a delay of about twenty-four hours in diagnosis. In one case 

 this delay amounted to five days, and in another to seven days. The 

 advantages claimed are tliat the medium is constant in composition, and 

 that it permits the growth of other organisms [e.g. Micrococcus miUtensis] 

 found in septicsemic conditions. 



New Method of Differentiating Bacillus typhosus, Paratyphosus 

 A and Paratyphosus B.* — E. Burnet and R. J. Weissenbach have 

 devised a new method for identification of typhoid and paratyphoid 

 organisms by means of culture on acetate of lead agar. The method is 

 stated to be simple, rapid and certain in its results, which have been 

 fully confirmed by agglutination reactions. To 4 c.cm. of heated agar 

 are added -^^^ c.cm. of a 10 p.c. fresh sterile solution of neutral acetate 

 of lead in distilled water. After mixing, the agar is allowed to reset, 

 a milky opacity Ijeing then observed. The platinum needle charged 

 with the organism to be investigated is insinuated between the side of 

 the test-tube and the column of agar with a slight rubbing motion. 

 Incubation is carried out at 37° C. In the case of BaciUiis paratyphoxus 

 B, a l>lack band appears along the track of the needle at the end of 

 eighteen hours ; with B. typhosus the l)and appears later (twenty-four 

 hours) and of a lighter colour. B. paratyphosus A does not blacken the 

 medium until after several days' growth. If the inoculation be made 

 direct from a hasmoculture in bile, the traces of blood and bile carried 

 over in the platinum loop must not be confounded with the reaction 

 produced by the disassociation of the lead salt. 



New Medium of Culture of Encapsulated Organisms. f — ^H. Cara- 



georgiades points out that there is a tendency in clinical bacteriology 

 to replace natural albuminous media (ascitic fluid, eggs, etc.), by com- 

 pounded albuminous media (Besredka's egg-broth, egg-agar, etc.), 

 the preparation of the latter media being easier and the steriMzation 

 more certain. Working on these Hues, the author has prepared a new 

 medium which, he states, may be employed with advantage as a sub- 

 stitute for the diagnostic medium of Bezan9on (young rabbit serum) 

 used for demonstration of capsulated organisms. The new medium is 

 prepared as follows : — 



To 66 c.cm. of distilled water are added 30 c.cm. of blood serum 

 of indifferent origin, 10 c.cm. egg-white, 10 drops of neutral glycerin, 

 and 0"5 c.cm. of deci-nornjal soda solution. Shake the mixture in a 

 250 c.cm. flask until thoroughly mixed, and autoclave at 115° C. for fifty 

 minutes. Filter warm through Chardin paper. Tube and re-sterilize 

 at 115° C. for ten minutes. The resulting medium is clear, of an amber- 

 yellow colour with opalescent reflections. It keeps well, but, in common 



* C.R. Soc. Biol., Paris, Ixxviii. (1915), pp. 565-8. 

 + C.R. Soc. Biol., Paris, Ixxviii. (1915), pp. 677-8. 



