374 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Detection of Bacillus Coli in Water.* — A. T. Venema uses the 

 following method for detecting B. coli in water. To 50 c.cm. of acid 

 bouillon (ordinary sterile broth that has not been made alkaline) is 

 added 5 c.cm. of water ; the mixture is then kept for 24 hours at 37° C. 

 From this culture fluid, plates on Drigalski-Conradi-lackmus agar, and 

 on Endo's fuchsin agar, are prepared ; the colonies of B. coli which 

 appear within 14-24 hours, are subjected to morphological and cultural 

 tests. By this method the author has succeeded in detecting this 

 organism in water, when other methods have failed to demonstrate its 

 presence. 



Rapid Filtration of Nutrient Agar.f — Babucke employs the fol- 

 lowing method :— 30 grm. of meat extract and pepton (Witte) is added to 

 300 c.cm. of boiling water, and stirred at boiling point until dissolved ; 

 the solution is then made up to 3 litres by addition of water, and the 

 whole heated to 100° C. ; 90 grm. of finely divided agar is then added, 

 and, when dissolved, the mixture is steam-sterilised for an hour. The 

 filter, previously sterilised, consists of a zinc funnel 21 cm. diameter at 

 the top and 3 cm. at the neck ; the top is covered with a four-fold layer 

 of fat-free wool, which, after soaking in water, is pressed down into the 

 funnel, though still extending over the rim. The prepared nutrient 

 agar is then poured out from the steamer in small quantities, on to the 

 wool filter. The filtration takes at slowest 20-25 minutes. By this 

 arrangement it is possible to obtain 3 litres of a 3 p.c. nutrient agar 

 within at most 2 hours. 



Cultivation of Bacillus Tuberculosis on Potato.f — J. Anzilotti 

 advocates the cultivation of B. tuberculosis on alkalin potato, using 

 Roux's tubes, in the bulb of which is 6 p.c. alkalin solution of glycerin. 

 The author finds that growth is more rapid and more vigorous than on 

 other media ; that the cultures retain their vitality longer without loss 

 of virulence, and possess a higher virulence and toxicity ; and are very 

 suitable for research purposes and for establishing homogeneous cultures 

 for the estimation of agglutination properties. 



Cultivation of Azotobacteria.§ — R. Perotti has detected the pres- 

 ence of an azotobacterium morphologically and culturally resembling the 

 Azotobacterium Chroococcum of Beijerinck, in ten different soils obtained 

 from various and widely separated districts of Italy. He pours into an 

 Ehrlenmeyer flask of 250 c.cm. content, 25 c.cm. of Beijerinck's solution, 

 and adds " 2 grm. of the soil |o be examined ; the whole is shaken and 

 allowed to stand at a temperature of 28° C. for 10 days, when it is 

 examined macroscopically and microscopically ; agar plates are made, and 

 sub-cultures are prepared on nutrient media containing greater or less 

 amounts of nitrogenous substances. 



Method of detecting Bacillus Anthracis in the Blood and Tissues.§ 

 J. Forster spreads plaster-of-paris plates moistened with Loeffler's bouil- 

 lon with a thin layer of the blood or material ; he finds that spore 



* Centralbl. Bakt., Orig. lte Abt., xl. (1906) p. 600. 



t Tom. cit., p. 607. J Tom. cit., p. 765. 



§ Atti R Accad. Lincei, xv. (1906) p. 295. 



|| Centralbl. Bakt., Orig. 1* Abt., xl. (1906) p. 751. 



