414 W. W. WILLIAMS AND W. BURDICK 



The tubes are left in their slanted position for about seventy- 

 two hours at room temperature until the contents are well set. 

 The cotton plugs are then trimmed and flamed and the tubes 

 sealed with corks. This medium presents the same smooth 

 inoculating surface as ordinary agar slants, contains as much 

 moisture, is quickly made and is rendered absolutely sterile. 



METHOD OF ISOLATING TUBERCLE BACILLI FROM SPUTUM 



About 10 cc. of fresh sputum, which has been thoroughly 

 washed in a ininning stream of sterile 0.85 per cent salt solution, 

 is placed in a sufficiently large centrifuge tube containing a 

 piece of blue litmus paper. An equal amount of 3 per cent 

 sodium hydroxid is added and the whole well shaken. It is 

 put in the incubator for about one hour or until the sputum is 

 fairly well digested. The mixture is neutralized with normal 

 hydrochloric acid, then centrifugalized, and after removing the 

 supernatant fluid the sediment is planted on several tubes con- 

 taining the herewith described medium by means of a large 

 platinum loop or a capillary pipette. After from five to four- 

 teen days incubation, a good growth appears which is free of 

 any contamination. 



This method has given us uniformly good results and the 

 medium remains serviceable for at least one month. 



REFERENCES 



Besredka, a. 1913 Compt. rend. Acad. d. sc, 156, 1633. 

 Churchman, John W. 1912 Jour. Exper. Med., 16, 221. 

 V. Drigalski and Conradi. 1902 Ztschr. f. Hyg., 39. 283. 

 Petroff, S. A. 1915 Jour. Exper. Med., 21, 38. 



