266 



SUMMARY OF CURRENT RESEARCHES. 



Fig. 69. 



New Method for Detection of Bacillus Coli Communis and Bacillus 



Typhi Abdominalis in Water.* — Mr. W. C. C. Pakes describes a method 



for detecting B. coli and B. typhosus in water, which has the advantage 



of being more delicate than those usually employed. The medium is 



glucose formate broth, which is composed of ordinary meat infusion, 



1 per cent, pepton, 05 per cent. NaCl, 2 per cent, glucose, and 0*4 per 



cent, sodium formate. After solution of the ingredients, the medium is 



N 

 neutralised, and then 2 ccm. of — KaHO added. The broth is then 



boiled in the steam steriliser for 20 minutes, filtered, poured into 

 test-tubes, and sterilised for 20 minutes on the day it is made and 

 the two succeeding days. After inoculation, the tubes 

 are placed in Buchner's tubes with alkaline pyro- 

 gallol (anaerobic cultivation) and incubated at 42° for 

 from 18-24 hours. An examination is then made, 

 and those tubes which show signs of growth are re- 

 moved. Incubation of the remainder is continued, 

 and examinations made at the end of 48 and 72 hours, 

 when, if there be no signs of the growth, the tubes 

 are rejected. Ordinary gelatin and agar-plates are 

 then made. 



In testing a sample of water for B. coli, large and 

 small quautities must be examined, and the water is 

 concentrated by passing it through a special filter, an 

 illustration of which is appended (fig. 69). After all 

 the water has run through, 10 ccm. of sterilised water 

 or bouillon are poured into the bougie, aud the bac- 

 teria brushed into the fluid. The emulsion represents 

 a concentration of 200 times; and 0*1 ccm. will re- 

 present 20 cm., and so on. A series of glucose for- 

 mate broth tubes is then inoculated with variable quan- 

 tities both of the original water and of the emulsion. 



Testing for Ergot in Flour.f— Fr. Musset demon- 

 strates the presence of ergot in flour by using 70 ccm. 

 of a mixture of chloroform and alcohol (about 10-1), 

 the specific gravity of which, at the time of examina- 

 tion, is to be brought up to 1*435 by the addition of absolute alcohol. 

 In this mixture 5 grm. of the suspected flour are shaken up, and after 

 having been allowed to settle, some of the floating scum is removed to 

 a cover-glass and allowed to dry. A little xylol is then added, and 

 the preparation examined microscopically. 



Bibliography. 



Carazzi, D. — Manuale di tecnica microscopica. xii. and 311 pp. Milano, 1899, 

 Duclaux, E. — Traite de Microbiologie. T. i. Microbiologic generate, 3 and 



632 pp. T. ii. Diastases, Toxines et Venins, 3 and 76S pp. Paris, 1899. 



Migula, W. — System der Bacterien : Handbuob der Morphologie, Entwicklungs- 



geschichte und Systematik der Bacterien. lid. i., 1897; Bd. ii., 1900. Jena. 



Lehmann, K. B„ und II. N e u m a n n —Atlas und Grundriss der Bacteriologie und 



Lehrbucb der speciellen bacteriologischen Diagnostik. 2. Auflage. 



Miinchen, 1899. 



* Brit. Med. Journ., 1900, i. pp. 188-9 (1 fig.). 



t Ph. Centr. Halle, 1899, p. 617. See Zeitscbr. Angew. Mikr., v.'(1899) pp. 230-1. 



