H. B. Hutchinson and J. Clayton 1 69 



substance might be of a dextrine nature and possibly the precursor of 

 saccharine compounds. Examination of numerous cultures of different 

 ages has failed, however, to indicate the presence of any breakdown 

 product capable of reducing Fehling's solution or possessing any optical 

 activity. The non-dextrin character of the mucilage is shown by the 

 results of an experiment in which a quantity of the substance was ex- 

 posed to the action of Taka-diastase. After treatment according to 

 the routine method the mucilage solution "failed to show even the 

 slightest trace either of sugar or dextrin." A further attempt was made 

 to obtain hydrolysis of the mucilage by means of fuming hydrochloric 

 acid. Under these conditions cellulose gives rise to the production of 

 dextrose; after digestion for three hours with hydrochloric acid, mucilage 

 solution was utterly lacking in optical activity ^. Hence a fundamental 

 difference exists between the nature of the mucilage and of cellulose. 

 On the other hand, the mucilage possesses certain points of resemblance 

 to the pectin or pectic acid group of compounds. On various occasions, 

 cultures of the organism have been reduced to dryness in vacuo and 

 extracted in alcohol to remove the pigment. On treatment of the residue 

 with cold water a shght, and with hot water a still greater, amount of 

 mucilage was brought into solution. After a partial concentration of 

 the extract the mucilage was thrown down with alcohol and filtered. 

 The residue, when treated with cold water, yielded a thick viscid fluid 

 which was extremely difficult to filter. On being heated, but without 

 being brought to the boil, the solution could be filtered with ease. 



It is, of course, probable that such a solution contains a whole range 

 of degradation products. Tannic acid fails to effect any precipitation. 

 On the addition of hydrochloric acid the solution is converted into a 

 thick jelly which on shaking and being allowed to stand, or on heating, 

 assumes the form of a light semi-transparent membranous precipitate. 

 Precipitation also results from the addition of barium and calcium 

 hydroxide, basic and neutral lead acetate, barium and calcium chloride, 

 silver nitrate and magnesium sulphate. 



The solution prepared in the above manner is neutral to litmus. 

 Treatment of the mucilage with hot dilute hydrochloric acid gives a 

 precipitate which is insoluble in water, but is readily soluble in ammonia, 

 from which it may again be thrown down on acidification. We thus 

 have a number of reactions which are also exhibited by pectin derivatives, 



^ We desire to express our indebtedness to Mr W. A. Davis and Mr E. Horton, of this 

 Laboratory, for kindly can-ying out the Taka-diastase and acid conversion tests respec- 

 tively. 



