32 THE SLIME OF THE HOUSEHOLD BATH-SPONGE, 



These guins are similar to one another, and are probably 

 identical. They are somewhat similar to the gum obtained from 

 Rhizobium legtominosarum, excepting in one or two reactions, as, 

 for example, Fehling's solution, with which the Rhizobium- gum 

 does not coagulate. Otherwise Rhizobium-gwm forms a jelly, 

 while these sponge-gums form mucilages. 



The bacterial gums were completely hydrolysed by boiling with 

 5% sulphuric acid, during which process furfural was evolved. 

 Before and after hydrolysis, the gum of Bac. ii., which had been 

 grown from levulose, was dextrorotatory. The solutions of the 

 sugars, obtained after neutralising the sulphuric acid with barium 

 carbonate and evaporating the filtrate to small bulk, were treated 

 with phenylhydrazine-acetic acid mixture, and the impure 

 osazones filtered oflf. 



These were purified by the method already described,* and 

 found to consist of galactosazone. No other osazone could be 

 detected, although crystalline osazone-like bodies with indefinite 

 melting points (140° to 155°) were obtained. I have previous!}' 

 suggested that these are probably derived from the furfuroid or 

 similar bodies. Upon oxidation with nitric acid the gums 

 3'ielded a mixture of oxalic and mucic acids. Thus the gums 

 were galactans. 



Bac. No. i. formed a dry, rough, scaly, glistening growth on 

 nutrient agar. In bouillon it grew scantily, chiefly as a surface 

 ring, and the fluid remained clear; nitrates were reduced to 

 nitrites and indol was formed. Litmus-milk was bleached, and 

 the casein slowly peptonised, the reaction becoming alkaline, 

 especially at the surface, where the dried casein appeared as a 

 broad, deep blue ring. In glucose-gelatin, the growth was trans- 

 lucent and rough, the medium becoming slowly liquefied; the 

 colonies were translucent and moruloid. In nutrient gelatin, 

 the growth was similar, but there was no liquefaction. On 

 potato there formed a transparent, flat, glistening growth which 



* These Proceedings, 1902, p. .394, and 1903, p. 546. 



