624 THE GUM FERMENTATION OF SUGAR CANE JUICE, 



on .agar show practically every variation from a slight, almost 

 transparent, watery smear to the luxuriant, corrugated, amoeboid, 

 tough layer over most of the agar surface. 



The Source of the Bacillus. 



It must not be presumed that the organism is derived from the 

 gum of "gummy cane," i.e., plants affected with gummosis. It 

 can be affirmed without a shadow of doubt that it does not, for 

 the reason that the gum which is found in gummed canes is 

 absolutely different from the gum formed by the bacillus. At 

 one time I thought it just possible that a different medium might 

 produce a different gum, and grew the bacillus in plant infusions 

 {e.g., hay, turnip) with sugar, but the gum produced in such 

 infusions was found to be identical with that formed in the pep- 

 tone solution. We can, therefore, say that the bacillus produces 

 only one kind of gum, viz., levan, which is absolutely different 

 from cane gum. 



The microbe has been separated from cane juice and from 

 refined sugars, and since it occurs in these two places — the 

 beginning and the end of the manufacturing process — it will 

 certainly be found in all positions in the factory and the refiner3^ 

 It undoubtedly obtains access to the factory with the cane,"^ 

 most probably on the outer surface of the plant. And having 

 once got into the manufactory, and being in congenial surround- 

 ings, it will thrive luxuriantly unless means are adopted to check 

 its growth. Experience has taught the manufacturer that the 

 best preventative for gumming is to push on the crystallisation 

 of the sugar as quickly and at as high a temperature as possible. 



* The bacillus was obtained from the interior of a portion of gummy cane 

 from Fiji, but as the portion had been lying about the benches in the labora- 

 tory of the Colonial Sugar Kefining Co. before it came into my possession, 

 there is the possibility that the organism obtained access to the centre of the 

 cane during that time. I sought for the bacihus in five samples of gummy 

 cane from New South Wales, and found it in the tissues of one of the 

 samples. 



