BY R. GREIG SMITH. 543 



common properties, and that the organism which I had separated 

 would eventually be found to be a pararabin-producer. 



The coagulation of the slime by all the reagents enumerated 

 is not characteristic of Sterculia slime, for I have already shown 

 that cane gum is also precipitated or coagulated. The slime of 

 Bact. persicce, the arabinan-galactan organism of the peach, etc., 

 when in strong solution, is also coagulated by these reagents. 

 The slimes of Bact. peisicce and Bact. vascularum difier from the 

 Sterculia bacterium slime, in that they are not resolved by treat- 

 ment in the autoclave at three atmospheres' pressure into a 

 deposit of bacterial remains and an almost clear or turbid super- 

 natant gummy fluid. In this respect there was an agreement 

 between the Sterculia bacterium slime and the slimes produced 

 by the arabin and the m'etarabin bacteria. 



The turbid solution of the gum, when treated with alcohol, 

 gave a precipitate which consisted of large curdy masses and 

 floccules. As the saline matter was removed during the process 

 of eliminating the last traces of sugar, the alcohol threw down a 

 precipitate, and at the same time produced a *' milk." The pre- 

 cipitate was only partly soluble in water; the alcohol had gradually 

 converted much of the carbohydrate into an insoluble modification. 

 Saline flocculating agents, such as potassium chloride or better 

 barium chloride, coagulated the "milk," and by dissolving the 

 precipitate in water an opalescent solution was obtained. 



The insoluble gum dissolved readily in dilute hydrochloric acid, 

 but boiling 1% sodium hydrate simply coagulated the diffused or 

 swollen carbohydrate, leaving a clear solution. The solubility in 

 dilute acid and insolubility in dilute alkali are characteristic of 

 par arabin. 



The slime was obtained by growing the bacterium upon the 

 surface of an agar medium containing 5% saccharose and 50% 

 potato juice. The potato juice and the medium should not be 

 neutralised at any time during its preparation. The natural 

 acidity undoubtedly favours the production of slime, causing it 

 to be more gummy and less opaque ; evidently there are less 

 bacterial cells and more gum. When neutralised potato juice is 



