BY R. GREIG SMITH. 167 



were but few colonies. The column marked "b(2)" shows the 

 reactions given by a second quantity of the gum of organism " b." 



Organism " b " was a large-sized spore-forming bacillus and 

 grew moderately well on saccharose-potato-agar, on which it pro- 

 duced a white slimy growth. In the slime the cells appeared to 

 preponderate. The slime, as has been already mentioned, did 

 not easily separate into gum and coaguluni. It had to be acidified 

 with several drops of dilute sulphuric acid, which, bearing in 

 mind that it was already acid, meant a stronger acidification than 

 is usually necessary with bacterial slimes. Acidification with 

 tartaric acid did not effect a separation even when the heating in 

 the autoclave was prolonged; this acid had been found very useful 

 during my earlier researches in gum-formation. After being 

 freed from reducing substances, by repeated precipitation from 

 aqueous solution with alcohol, the gum was boiled with 5% 

 sulphuric acid for six hours. Portions of the solution when 

 tested showed the presence of reducing sugars and the absence of 

 gum precipitable with alcohol. The osazones were prepared in 

 the usual manner, and after purification from tarry bodies 

 were separated into galactosazone, and another with a melting 

 point near 170^ The latter was very difiicult to separate from 

 the former as, although it was more soluble in alcohol, water and 

 ether, the difference in solubility was not sufficiently pronounced 

 to enable the separation to be easily effected. 



Thus the gum formed by the bacterium has been found to con- 

 tain an anhydride of galactose and another substance which 

 yields an osazone having a melting point near 170°. 



Organism " a " was by far the most numerous bacterium in 

 the tissues of the plants, if the colonies that developed on the 

 plates were any criterion. Its slime was more viscous than that 

 of the others, and this would accentuate the relative preponder- 

 ance on account of the tendency of the cells to aggregate, many 

 giving rise to one colony. The reactions of the gum are very 

 similar to those given by average Linseed gum, the only difference 

 being with neutral lead acetate. Upon levulose-asparagine-agar, 

 with or without tannin, it produced a tough slime which yielded 



