78 HISTORY AND CAUSE OF THE COCONUT BUD-ROT. 



Dr. B. H. Stone ^ describes a rapid method of identifying Bacillus 

 coli in water. A fermentation tube is filled with 2 per cent glucose 

 bouillon and this is inoculated with 1 cubic centimeter of the water to 

 be examined and grown 24 hours at 38° C. If from 25 to 70 per 

 cent of gas is formed in the closed arm Bacillus coli is probably present. 

 From those tubes which produce this amount of gas transfers of 0.5 

 c. c. are made to tubes containing 10 c. c. of neutral broth to which 

 has been added 0.3 c. c. of Parietti's solution, and the tubes are 

 grown 24 hours at 38° C. From those tubes containing Parietti's 

 solution transfers of 0.5 c. c. are made to fresh fermentation tubes, 

 and if gas is produced as before there is reasonable certainty that the 

 organism is Bacillus coli. Further confirmation is obtained by ascer- 

 taining the gas formula, that of the colon group being H:C02::2:1. 



Further transfers from the supposed Bacillus coli may be made into 

 gelatin stab cultures, into litmus milk, and into Dunham's solution for 

 indol. Also the morphology may be ascertained. These reactions 

 are considered by Dr. Stone sufficient to verify the identification of 

 Bacillus coli. 



Drs. F. F. Longley and W. U. C. Baton- have pubhshed their routine 

 method for identifying Bacillus coli in water, as follows: 



1. Incubation in ordinary dextrose broth and fermentation tubes at 40° C. for 24 

 hours. From those tubes showing gas within 24 hours transfers are made to litmus- 

 lac tose-agar plates. 



2. The litmus-agar plates are incubated at 40° C. for 18 to 26 hours. From those 

 colonies which appeared red on these plates transfers are made to agar slants. 



3. Agar slants are incubated for 24 hours at 40° C. Those slants which have the 

 typical cultures characteristic of Bacillus coli are not examined microscopically. 

 Atypical colonies are examined before discarding. 



4. A. Those agar slants which show typical cultures are transferred to dextrose broth 

 fermentation tubes and incubated at 40° C. for 24 hours. The absence of gas is con- 

 sidered negative. The quantity of gas present and the proportion of COg are not 

 determined. 



4. B. Milk. Transfers to milk cultures are incubated at 40° C. for two days and 

 examined daily for coagulation and _ digestion of the casein. Coagulation indicates 

 Bacillus coli. 



4. C. Nitrate broth cultures. Incubated at 40° C. for two days and then tested for 

 nitrites. The presence of nitrites indicates Barillus coli. 



4. D. Peptone broth. Cultures incubated for three days at 40° C. and tested for 

 indol. Presence of indol indicates Bacillus coli. 



> Stone, B. H. A Rapid Method of Detecting Bacillus Coli Communis in Water. American Medicine, 

 vol. 3, Jan. 25, 1902, p. 1.54. 



' Longley, F. F., and Baton, \V. U. C. Notes on the Determination of Bacillus Coli in Water. Journal 

 of Infectious Diseases, vol. 4, 1907, pp. 397-416. 



228 



