330 Mr. F. W. Twort. Fermentation of Glueosides by [Mar. 7, 



On utilising these sugar tests, MacConkey was able to differentiate such 

 closely allied bacteria as B. coli, Escherich, B. acidi lactici, Hueppe, B. lactis 

 aerogenes, Escherich, and B. pneumoniae, Friedlander. 



It was with a view to obtaining other fermentation tests which might be 

 of service in separating organisms still remaining undifferentiated that the 

 following experiments with glueosides were undertaken. 



In carrying out these tests, an ordinary peptone water medium containing 

 2 per cent, of the glucoside to be tested was used. Such a medium was 

 distributed in a number of test tubes, each of which contained a small 

 inverted glass tube sealed at the upper end after the method recommended 

 by Durham. In one series of experiments litmus solution was purposely 

 left out of the medium to see whether any colour change might be observable 

 in the glucoside under examination. In another series 5 per cent, of 

 Kahlbaum's litmus solution was added, the medium being otherwise identical 

 with the above. All the glueosides used were obtained from Merck. 



In the case of insoluble glueosides an amount was added to the peptone 

 water which would represent a 2-per-cent. solution. 



All those media containing glueosides which by their colour obscured the 

 reaction of the litmus solution were repeatedly tested on litmus paper 

 during the growth of the organism. 



Forty-nine glueosides were tested with the following 18 species of bacteria 

 belonging to the typhoid-coli group : — 



B. fcecalis alcaligenes, Petruschky. 



B. dysenterice, Kruse. 



Flexner (Pseudo-dysentery IV of Firth). 



B. typhosus, Eberth-Gaffky. 



B. paratyphosus, Brion and Kayser. 

 „ Schottmuller. 



B. enteritidis, Gaertner. 



B. paracoli, Widal. 



B. coli, Escherich. 



B. pneumoniae, Friedlander (MacConkey strain). 

 „ „ (laboratory strain). 



„ „ (Krai strain). 



B. neapolitanus, Emmerich. 



B. pyogenes foetidus, Passet. 



B. acidi lactici, Hueppe. 



B. lactis aerogenes, Escherich. 



B. capsulatus, Pfeiffer. 



B. cloacce, Jordan. 



