84 



A Sugar Bacterium. 



Attention has been called in the first part of this paper to the 

 amount of viscous material which the bacterium produces in solutions 

 of cane sugar. There is a great similarity between its action in this 

 respect and that of Van Tieghem's Leuconostoc. 



An examination was made of the viscous material, a special culture 

 being made in a large flask for the purpose. The slimy material was 

 found to be slowly soluble in water, yielding an opalescent solution. 

 When poured into an excess of alcohol, it gave a bulky flocculent pre- 

 cipitate. This was allowed to settle and the alcohol was decanted, and the 

 wet precipitate thrown on to a filter. When all the spirit had drained 

 away, it was taken from the filter and stirred with water in a beaker. 

 A considerable quantity dissolved, but a good deal of residue was left 

 in suspension. The watery solution was filtered off and examined. 



It gave a reddish-purple colour on the addition of iodine, but had no 

 action on Fehling's fluid. Heated with 2 per cent, of sulphuric acid 

 on a water-bath for two hours and then neutralised, it gave evidence 

 of the presence of sugar. It reduced Fehling's fluid on boiling, and 

 yielded an osazone when treated with phenylhydrazine acetate. It 

 deflected a ray of polarised light, and had a specific rotatory power of 

 [a] D = +130. 



The residue, which was insoluble in water, was coloured violet on 

 the addition of iodine. It had no action on Fehling's solution, but 

 was converted into a reducing sugar by boiling it with 2 per cent, of 

 sulphuric acid. It was readily soluble in a 10 per cent, solution of 

 caustic soda, and less freely in a 1 per cent, solution. Neutralisation 

 or dilution did not cause it to be reprecipitatecl. The solution had no 

 action on polarised light. 



There were thus found to be present in the viscous liquids two dis- 

 tinct carbohydrates, which possessed much in common with Scheibler's 

 dextran, but which were not quite identical with the latter. They both 

 appeared to be members of the hemi-celluloses. 



The exact relation of these bodies to the bacterium has not been 

 determined. While there are some grounds for thinking that they are 

 not so much products of fermentation in the strict sense as of its ordi- 

 nary biological processes, being perhaps only the substance of the 

 different sheaths to which allusion has been made in the first part of 

 this paper, it is not certain that they may not be regarded as products 

 produced altogether outside the organism, in consequence of an altera- 

 tion of the fructose produced by the hydrolysis. It is altogether 

 unlikely that they resulted from the glucose moiety of the inversion, 

 as this sugar is not a favourable medium for the growth of the organ- 

 ism, and such cultivations as are possible in solutions of glucose do not 

 show the presence of any viscous material. 



