BY R. GREIG SMITH. 165 



posed to any extent by boiling 5 % acid, and their osazones are 

 not destroyed when heated with dilute acetic acid, for I have 

 repeatedly obtained their osazones during my researches in con- 

 nection with the bacterial origin of the gums. It would appear 

 tliat the method devised by Hilger for the recognition or separa- 

 tion of arabinose, glucose, galactose and xylose is not capable of 

 distinguishing between the first two sugars and substances that 

 may be closely allied. Glucosazone is one of the easiest osazones 

 to isolate, and it undoubtedly was not among the products of 

 hydrolysis of the gum. 



With the object of examining the tissues of the plant to deter- 

 mine the nature of the gum that "might be produced by the 

 bacteria contained therein, I obtained several plants from the 

 Hawkesbury Agricultural College, and these were subjected to 

 the usual bacteriological process for the separation of the 

 individual organisms. The bacteria were, comparatively speak- 

 ing, very numerous, and the majority were capable of producing 

 slime upon media containing saccharose or levulose. The organ- 

 isms were found not only in the capsules but also in the stems, 

 where they preponderated. There were many kinds, but those 

 that appeared to be similar were grouped together, and from each 

 group one organism was selected. These were gradually nar- 

 rowed down to what appeared to be three species. There were 

 many races of these species, and that race which seemed to pro- 

 duce the most slime was taken as the representative of the 

 species. 



Obviously the iirst thing to be done was to obtain the gums 

 from these bacteria in sufficient quantity for testing so that they 

 could be compared with the gum from the natural mucilage. It 

 is here that the indefinite nature of Linseed gum is found to be 

 so troublesome. The only reactions that were constant were 

 obtained with alcohol, basic lead acetate and tannin. As the 

 first two reagents coagulate practically every gum, the}' are of 

 little value for the recognition of different gums. Then the pro- 

 ducts of hydrolysis furnish indefinite osazones. In short, it 

 appeared that it would be difficult to trace any relationship 



